Sagot :
Bonjour,
C = (x - 7)(x + 9)
= x*x + x*9 - 7*x - 7*9
= x² + 2x - 63
D = (-2x + 8)(4 - x)
= -2x*4 - 2x*(-x) + 8*4 + 8*(-x)
= -8x + 2x² + 32 - 8x
= 2x² - 16x + 32
Bonjour,
C = (x - 7)(x + 9)
= x*x + x*9 - 7*x - 7*9
= x² + 2x - 63
D = (-2x + 8)(4 - x)
= -2x*4 - 2x*(-x) + 8*4 + 8*(-x)
= -8x + 2x² + 32 - 8x
= 2x² - 16x + 32