plissss yang baikkk jawab,,,,

a = ayah
x = roni

a = 1 1/5 . x
a - x = 30
1 1/5 x - x = 30
1/5 x = 30
x = 30 . 5
umur roni= 150 cm
umur ayah = 150 + 30
= 180 cm