a)
[tex]x( - 2x + 1) + 3x(x - 2) = \\ \\ = - 2 {x}^{2} + x + 3 {x}^{2} - 6x = \\ \\ = \boxed{ x {}^{2} - 5x} \\ \\ daca \: vrei \: sa \: dai \: factor \: comun \\ = x(x - 5)[/tex]
b)
[tex](2x + 3)(x - 1) + (3x - 2)( - x + 5) = \\ \\ = 2x {}^{2} - 2x + 3x - 3 - 3x {}^{2} + 15x + 2x - 10 = \\ \\ = \boxed{- x {}^{2} + 18x - 13}[/tex]
