Question

Find the coefficient of the 4th term in expansion of (x +2 )^5

Answer 1

$(x + 2)^5=(x+2)^2\cdot{(x+2)^2}\cdot{(x+2)}\\\\(x+2)^5=(x^2+4x+4)\cdot{(x^2+4x+4)}\cdot(x+2)$

$(x+2)^5=(x^4+8x^3+24x^2+32x+16)\cdot(x+2)$

$(x+2)^5=x^5+10x^4+40x^3+80x^2+80x+32$

10