bonjour

f (x) = 2.5 x - 1

f (0) = - 1

f (2) = 2.5 * 2 - 1 = 5 - 1 = 4

2.5 x - 1 = 3

2.5 x = 3 + 1

2.5 x = 4

x = 1.6

g(x) = - 0.5 x + 2

- 0.5 x + 2 = 0

- 0.5 x = - 2

x =  4

2.5 x - 1 = - 0.5 x + 2

2.5 x + 0.5 x = 2 + 1

3 x = 3

x = 1