One application of linear equations is what are termed age word problems. When solving age problems, generally the age of two different people (or objects) both now and in the future (or past) are compared.
From the given information:
The sum of Ben's and David's ages is 62 yrs now
And
Five years from now David will be twice as old as Ben.
Let the ben age is x
and the david age is y.
So, from given information:
x+y = 62 -(1)
5 years from now,
y = 2x -(2)
put (2) in the (1) then
x+y = 62 -5
x+2x = 57
3x = 57
x = 19.
And the age of davud become
y = 2(19)
y = 38 years
So, five years from now the age of ben is 19 and david is 38 years.
