Question

find the coefficent of x^5 in the expansion of (1+2x)^5.(1-x)7

Answer 1

$(1 + 2x) {}^{5} .(1 - x)7 \\ {1}^{5} + {2x}^{5} \times 7 - 7x \\ here \: the \: coefficent \: of \: x \: is2$