Question

Tìm x:

a) 5(x-3)(x-7)-(5x+1)-(x-2)=8

b) 3(x-7)(x+7)-(x-1)(3x+2)=13

Answer 1

b)  \(3\left(x-7\right)\left(x+7\right)-\left(x-1\right)\left(3x+2\right)=13\)

\(\Leftrightarrow\)\(3\left(x^2-49\right)-\left(3x^2-x-2\right)=13\)

\(\Leftrightarrow\)\(3x^2-147-3x^2+x+2=13\)

\(\Leftrightarrow\)\(x-145=13\)

\(\Leftrightarrow\)\(x=158\)

Answer 2

Bài 1:

a, 5x(x-3)(2x+4)-((x+7)(x-3)+(5x-2)(3x+4)