Răspuns:
3.
f(3a) = -2a - 3
f(3a) = -12a + 7
-12a + 7 = -2a - 3
-10a = -10
a = 1
4.
-3x + 7 = -8x - 3
- 3x + 8x = -7 - 3
5x = -10
x = -2
f(-2) = 13 => M(-2, 13)
5.
f(2) = 3 => 2a + b = 3 |•(-1)
f(4) = 7 => 4a + b = 7
-2a - b = -3
4a + b = 7
________+
2a / = 4 => a = 2 => b = (-1)
=> f(x) = 2x - 1