Répondre :
(-2x+1)(x+4)=3(4x-2)(x+1)
-(2x-1)(x+4)-3(4x-2)(x+1) = 0
-(2x-1)(x+4)-6(2x-1)(x+1) = 0
(2x-1)(x+4)+6(2x-1)(x+1) = 0
(2x-1)(x+4+6x+6) = 0
(2x-1)(7x+10) = 0
2 solutions :
x = 1/2
ou
x = -10/7
f(20) = -125/3 et f(-17)=134/3
y = ax + b
-125/3 = 20a + b
134/3 = -17a + b
-125/3 - 134/3 = 20a + 17a
259/3 = 37a
a = 259/111
b = 134/3 - 17*259/111
b = 134*111/333 - 4403*3/333
b = (14874 - 13209)/333
b = 1665/333
donc f(x) = 259x/111 + 1665/333
En espérant t'avoir aidé.
(-2x+1)(x+4)=3(4x-2)(x+1)
-(2x-1)(x+4)-3(4x-2)(x+1) = 0
-(2x-1)(x+4)-6(2x-1)(x+1) = 0
(2x-1)(x+4)+6(2x-1)(x+1) = 0
(2x-1)(x+4+6x+6) = 0
(2x-1)(7x+10) = 0
2 solutions :
x = 1/2
ou
x = -10/7
aprés je sais pas :/