(5-x) ² - (3x-2) ⋅ (2x+1) = x⋅(2-5x).
(5-x)²-(3x+2)(2x+1)=x(2-5x) 25-10x+x²-(6x²+3x+4x+2)=2x-5x² 25-10x+x²-6x²-3x-4x-2=2x-5x² x²-6x²+5x²-10x-3x-4x-2x=-25+2 -19x=-23 19x=23 x=