Tính (4x² - 5x) (3x + 2) + 7x (x + 5) = (-4 + x)(-2x + 3) + 12x³ + 2x²
8) (4x²-5x) (3x+2)+7x (x+5)=(-4+ x)(-2x+3)+12x³ + 2x²
9) -5x2 (2x+5)+(5x-7) (5x+1)=(5x2-4) (-2x+3)-3x (5x-1)
10) (x-7)(2x² - 4) - 2x²(x+7)=(5x+3)(2x-4) - 19x(2x-1)
11) (-4x²-3)(2x + 5) - (8x - 3)(-x² + 2) = -5x(4x-6) - 3x²-4
12) (x-7)(x+5)-(x-3)(x-2) = 15x²(x + 1) - (3x-1)(5x-2)- 20x2
13) (3x-5) (5x-7) - 15x(x-2)=(6x-1)(3x + 2) - (9x + 1)(2x - 1)
14) (9x2-5)(x+3)-3x² (3x+9) = (x-5)(x+4)-x(x²-11)
15) (x-3)(-x+10)+(x-8)(x+3)=(5x² −1)(x+3)- 5x³-15x²
16) -7x² (x+5)-(x²-4)(-7x-5)=(15x-1) (-2x+1)-7x+2
17) (6x-1)(x-3)-(2x-3) (3x+2)=(x+4)(x-6)-x(x+3)
18)
(5x+4)(x-7)-5x(x-5)=(x²-7)(x+4)-x2(x-3)-7x2
19) (12x²-1)(x+3)-(4x²-5)(3x+9)=(x-8)(x+2)-x-9
20) (-2x² +5)(-x+3)-x² (2x-6)=(x 1)(x+1)-(x-2)(x+4)
9) -5x2 (2x+5)+(5x-7) (5x+1)=(5x2-4) (-2x+3)-3x (5x-1)
10) (x-7)(2x² - 4) - 2x²(x+7)=(5x+3)(2x-4) - 19x(2x-1)
11) (-4x²-3)(2x + 5) - (8x - 3)(-x² + 2) = -5x(4x-6) - 3x²-4
12) (x-7)(x+5)-(x-3)(x-2) = 15x²(x + 1) - (3x-1)(5x-2)- 20x2
13) (3x-5) (5x-7) - 15x(x-2)=(6x-1)(3x + 2) - (9x + 1)(2x - 1)
14) (9x2-5)(x+3)-3x² (3x+9) = (x-5)(x+4)-x(x²-11)
15) (x-3)(-x+10)+(x-8)(x+3)=(5x² −1)(x+3)- 5x³-15x²
16) -7x² (x+5)-(x²-4)(-7x-5)=(15x-1) (-2x+1)-7x+2
17) (6x-1)(x-3)-(2x-3) (3x+2)=(x+4)(x-6)-x(x+3)
18)
(5x+4)(x-7)-5x(x-5)=(x²-7)(x+4)-x2(x-3)-7x2
19) (12x²-1)(x+3)-(4x²-5)(3x+9)=(x-8)(x+2)-x-9
20) (-2x² +5)(-x+3)-x² (2x-6)=(x 1)(x+1)-(x-2)(x+4)