help me la~問題大王?(方程式應用題)

設媽媽現在的年齡是x歲

x + 10 + x/3 + 10 = 74
4x / 3 = 54
x = 40.5

設兒子的年齡是x
3x+10+x=74
4x+10-10=74-10
4x=64
4x/4=64/4
x=16
∴兒子的年齡是16,媽媽的年齡是3x16
=48

let x be the age of mum
and y be her son's age

x=3y........(1)
(x+10)+(y+10)=74.........(2)

(1)
y=x/3

sub y =x/3 in (2)
x+10+x/3+10=74
x+x/3=54
3x+x=162
4x=162
x=40.5