Bonjour,
1) f(3) = 5 × 3 + 2 = 15 + 2 = 17
2) f(-6) = -6 × 5 + 2 = -30 + 2 = -28
3) f(2/3) = 5 × (2/3) + 2 = 20/6 + 12/6 = 32/6 = 16/3
4) 5x + 2 = 22
5x = 22 - 2
5x = 20
x = 20/5
x = 4
5) 5x + 2 = -28
5x = -28 - 2
5x = -30
x = -30/5
x = -6
6) 5x + 2 = -2
5x = -2 - 2
5x = -4
x = -4/5