Question

ПОМОГИТЕ С АЛГЕБРОЙ СРОЧНО ПЖ

Answer 1

$y=x^{9} +3x\\\\y'=(x^{9} )'+3(x)'=9x^{8}+3*1=9x^{8}+3\\\\y''=9(x^{8})'+3'=9*8x^{7} +0=72x^{7}\\\\\boxed{y''=72x^{7}}$