bonjour
f (x) = - 2 x + 5
f ( - 7 ) = 14 + 5 = 19
g (x) = - 2 x² + 13 x - 15
g ( 1/3) = - 2 ( 1 /3 )² + 13 * 1/3 - 15 = - 2 * 1/9 - 13 /3 - 15
= - 2 /9 + 39/9 - 135/9 = - 98 /9
- 2 x + 5 = - 3
- 2 x = - 3 - 5
- 2 x = - 8
x = 4
( 2 x - 3 ) ( 5 - x ) = 10 x - 2 x² - 15 + 3 x = - 2 x² + 13 x - 15
( - 2 x - 3 ) ( 5 - x ) = 0
x = - 3/2 et 5
je te laisse faire le tableau
