Jawabanmu

2013-12-16T21:18:16+07:00
Misal umur ayah sekarang = a
umur anak sekarang = b
Sehingga ;
a - 2 = 6(b - 2)
a - 2 = 6b - 12
a = 6b - 12 + 2
a = 6b - 10 ........(1)

a + 18 = 2(b + 18)
a + 18 = 2b + 36
a - 2b = 36 - 18
a - 2b = 18 .......(2)

(1) substitusi ke (2)
a - 2b = 18
6b - 10 - 2b = 18
4b = 18 + 10
4b = 28
b = 7

a = 6b - 10
...= 6(7) - 10
...= 42 - 10
a = 32

a + b = 32 + 7
........= 39


jadi jumlah uur mereka 39 tahun


1 2 1