Question

a) (-x+4)×(x+5)
b) (2x+y)×(x-y)
c) (xy-7)×(xy-6)
d) (3x-7)×(2x-4)​

Answer 1

Explicação passo-a-passo:

a) (-x +4).(x+5)= - x² -5x +4x +20

= - x²-x+20

b) (2x+y).(x-y)= 2x² -2xy +xy -y²=

2x² - xy -y²

c) (xy-7).(xy-6)= x²y² -6xy -7xy + 42=

x²y² -13xy +42

d) ( 3x -7).(2x-4)= 6x² -12x - 14x + 28=

6x² - 26x +28