bonjour
h = ( x - 4)² - x ( x - 10)
a) H = x² - 8 x + 16 - x² + 10 x
H = 2 x + 16
b) 2 x + 16 = 16
2 x = 16 - 16
2 x = 0
x = 0
2) I = ( 7 x - 3)² - 5²
I = ( 7 x - 3 - 5) ( 7 x - 3 + 5)
I = ( 7 x - 8) ( 7 x + 2)
I = 0
soit 7 x - 8 = 0 , soit 7 x + 2 = 0 donc
soit x= 8/7 , soit x = - 2/7