Question

Tìm x, biết

 ( x+7) +3x (2x-1) -2x (3x+15)= -42

Answer 1

\(\left(x+7\right)+3x\left(2x-1\right)-2x\left(3x+15\right)=-42\)

=>\(x+7+6x^2-3x-6x^2-30x=-42\)

=>\(-32x=-42-7=-49\)

=>\(x=\dfrac{49}{32}\)