C. -x + 4
D. -5x + 5
E. -5x + 15
pembahasan :
x + 1 jadi -1a + b = 10
2x - 3 jadi 3/2 a + b = 5
kemudian, lakukan eliminasi :
-1a + b = 10 x 2 => -2a + 2b = 20
3/2 a + b = 5 x 2
-2a + 2b = 20
3a + 2b = 10
______________-
- 5a = 10
a = 10/-5
a = -2
-1a + b = 10
-1.(-2) + b = 10
2 + b = 10
b = 10- 2
b = 8