Question

(x+4)(x+4)(x+4). what is the coefficient of x square??

Answer 1

$(x + 4)(x + 4)(x + 4) = {(x + 4)}^{3} \\ \\ = {x}^{3} + 64 + 3 {x}^{2} \times 4 + 3x16 \\ = {x}^{3} + 64 + 12 {x}^{2} + 48x$
so coefficient of x^2 is 12