Sagot :

Bonjour,

A=3(x+6)-(x-8)

= 3x +18 -x +8

= 2x +26

B=(x+1)(x-9)

= x² -9x +x -9

= x² -8x -9

C=(4-x)² +4x

= 16 -8x +x² +4x

= x² -4x +16

D=(2x-8)(2x+8)

= 4x² +16x -16x -64

= 4x² -64