Question 1027805
Hi there,
in fourteen years time mother 
will be twice as old as her son. 
M + 14 = 2(S + 14).......(1)
Four years ago the sum of their 
ages was thirty. 
M - 4 + S - 4 = 30.......(2)
Consider Equation(1)
M + 14 = 2(S + 14).......(1)
M + 14 = 2S + 28
M = 2S + 28 - 14
M = 2S + 14
Substitute (2S + 14) for M in Equation(2)
M - 4 + S - 4 = 30.......(2)
(2S + 14) - 4 + S - 4 = 30
2S + 14 - 4 + S - 4 = 30
Collect like terms:
2S + S = 30 - 14 + 4 + 4
3S = 24
S = 8
Using Equation(1)
M + 14 = 2(S + 14).......(1)
M + 14 = 2(8 + 14)
M + 14 = 2(22)
M + 14 = 44
M = 44 - 14
M = 30.
At present time:
Son is 8 years old
Mother is 30 years old
When the boy was born the mother's
age was 30 - 8 = 22 years old.
Hope this helps :-)