Question

B) (4x+2).(-2x+4)=

C) ( -x-10).(2x- 4)=

D) (1,2x+ 5). (2- 4,3x )=

Answer 1

b)
(4x + 2). (- 2x + 4)
= 4x.(-2x) + 4.4x + 2.(-2x) + 2.4
= - 8x² + 16x - 4x + 8

= - 8x² + 12x + 8

c)
(- x - 10). (2x  - 4)
= - x.(2x) - x.(- 4) - 10.2x - 10.(- 4)
= - 2x² + 4x - 20x + 40

= - 2x² - 16x + 40

d)
= (1,2x + 5). (2 - 4,3x)
= 2.1,2x + 1,2x . (- 4,3x) + 5.2 + 5.(-4,3x)
= 2,4x - 5,16x² + 10 - 21,5x

= - 5,16x² - 19,1x + 10