1. Ditentukan f(x)4x+3. Jika f(a)=27 maka nilai a adalah ... A. 4 B. 6 C. 8 D. 10 2. Fungsi h dinyatakan dengan rumus h(x)=ax+b. Jika h(5)=-42 dan h(-2)=7 maka

1. kalo gk A berati B
2.29
3.D
4.-5

maaf kalo salah

1) f(x) = 4x + 3
f(a) = 4a + 3 = 27
4a = 27 - 3
4a = 24
a = 6 ( B )

2) h(x) = ax + b
h(5) = 5a + b = - 42
h(-2) = - 2a + b = 7
----------------------------(-)
7a = - 49
a = - 7
subtitusi
- 2a + b = 7
- 2(-7) + b = 7
14 + b = 7
b = 7 - 14
b = - 7
h(x) = - 7x - 7
h(12) = - 7(12) - 7 = - 84 - 7 = - 91 ( A )

3) 2x + 3y = 6
x - 2y = - 4 |×2
maka
2x + 3y = 6
2x - 4y = - 8
------------------(-)
7y = 14
y = 2
subtitusi
x - 2y = - 4
x - 2(2) = - 4
x - 4 = - 4
x = - 4 + 4
x = 0
hp = ( 0,2 ) ( B )

4) y = x + 5
subtitusi
x + 3y = 15
x + 3(x + 5 ) = 15
x + 4x + 15 = 15
5x = 15 - 15
5x = 0
x = 0
subtitusi
y = x + 5
y = 0 + 5
y = 5
hp = { 0,5 }
x - y = 0 - 5 = - 5 ( B )