Sagot :
3) f = ax + b
B(-2,-3) => -3 = -2a + b
C(2;1) => 1 = 2a + b => 2b = -2 => b = -1 => 2a = 1 - b = 1+1 => 2a = 2 => a = 1
f(x) = x - 1
4) g(x) = ax + b
A(1;2) => 2 = a + b
D(3;0) => 0 = 3a + b => 2a = -2 => a = -1 => 2 = -1 + b => b = 3
g(x) = -x + 3