bonjour
1. 1 *0.5 + b = 3
0.5 + b = 3
b = 3 - 0.5
b = 2.5
f( x) = 0.5 x + 2.5
2. ( 7 - 3 ) / ( 3 + 2) = 4/5 = 0.8
h ( - 2) = 3
- 2 *0.8 + b = 3
- 1.6 + b = 3
b = 3 + 1.6 = 4.6
h (x) = 0.8 x + 4.6
h ( 3) = 3 *0.8 + 4.6 = 7 donc on est bon
0.5 x + 2.5 = 0.8 x + 4.6
0.5 x - 0.8 x = 4.6 - 2.5
- 0.3 x = 2.1
x = 7