Question

Cu cat este egal x :
(4x-3)-9(x+5)(x-2)=7(x+2)-8
(4x+3) este la puterea a doua si
(x+2) din partea dreapta e la puterea a doua.

Answer 1

$\displaystyle (4x-3)^2-9(x+5)(x-2)=7(x+2)^2-8 \\ (4x)^2-2 \cdot 4x \cdot 3+3^2-9(x^2-2x+5x-10)=7(x^2+2 \cdot x \cdot 2+2^2)-8 \\ 16x^2-24x+9-9(x^2+3x-10)=7(x^2+4x+4)-8 \\ 16x^2-24x+9-9x^2-27x+90=7x^2+28x+28-8 \\ 16x^2-9x^2-7x^2-24x-27x-28x=28-8-9-90 \\ -79x=-79 \Rightarrow x= \frac{-79}{-79} \Rightarrow x=1$