Sagot :
1) 7x2 + 2x - 12
2) 15 - 6x
3) x - 7x2 + 11
4) -5x +2x2 - 15 + 6x
2) 15 - 6x
3) x - 7x2 + 11
4) -5x +2x2 - 15 + 6x
Bonjour
A = 7x²- 8
B = - 5 + 2x
C = x + 3
a. A + B = 7x² - 8 - 5 + 2x = 7x² + 2x - 13
b. (- 5 + 2x) * 3 = - 15 + 6x
L'opposé est : 15 - 6x
c. C - A = (x + 3) - (7x² - 8) = x + 3 - 7x² + 8 = - 7x² + x + 11
d. B x C = (- 5 + 2x) (x + 3) = - 5x - 15 + 2x² + 6x = 2x² + x - 15.