Question

Efectuati:
a) (5x-7) x [2(x+2) +3 (x+1)]-(4x-3)x [3(x+3)+x -6 ]=
b) (x+1)x [5(x+1)-2(x+4)]-(3x+2)x [7(x+2)-4(x+3)]=

Answer 1

a) (5x + 7) x (2x + 4 + 3x +3) - (4x - 3) x (3x + 9 + x - 6) =
    (5x + 7)(5x + 7) - (4x - 3)(4x - 3) =
    [(5x+7)+(4x-3)][(5x+7)-(4x-3)] =
    (9x + 4)(x + 10) =
    9$x^{2}$ + 94x + 40
 

b) (x + 1)(5x + 1 - 2x - 8) - (3x + 2)(7x + 14 - 4x - 12) =
(x + 1)(3x - 7) - (3x + 2)(3x + 2) =
3$x^{2}$ - 4x - 7 - 9$x^{2}$ - 12x - 4 =
-6$x^{2}$ -16x - 11