Question

Thu gọn biểu thức:

A= x(10x+7)-(5x-1)(2x+3)+13x

Answer 1

\(A= x(10x+7)-(5x-1)(2x+3)+13x\\ = 10x^2+7x-(10x^2+15x-2x-3)+13x\\ = 10x^2+7x-10x^2-15x+2x+3+13x\\ = 7x+3\)

Answer 2

\(A=x.\left(10x+7\right)-\left(5x-1\right).\left(2x+3\right)+13x\)

\(A=10x^2+7x-\left(10x^2+15x-2x-3\right)+13x\)

\(A=10x^2+7x-10x^2-15x+2x+3+13x\)

\(A=\left(10x^2-10x^2\right)+\left(7x-15x+2x+13x\right)+3\)

\(A=7x+3.\)

Chúc bạn học tốt!