(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

-1

-2

-3

-4

লগইন করুন

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

(1=x)n=1-2x=3x-4x3=.....(-1)r(r+1)xr=...... হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?

$(1 = x)^{n} = 1 - 2 x = 3 x - 4 x^{3} = . . . . . (- 1)^{r (r + 1)} x^{r} = . . . . . .$ হলে n=?