Answer:
Step-by-step explanation:
Let the age of a man = x
Age of his brother = y
Three yrs hence, a man will be three time his brother age
This is written as:
x + 3 = 3(y + 3)
x + 3 = 3y + 9 .... Equation 1
The sum of present age is 18
= x + y = 18
x = 18 - y
We substitute 18 - y for x in Equation 1
find their present age
18 - y + 3 = 3y + 9
Collect like terms
21 - 9 = 3y + y
12 = 4y
y = 12/4
y = 3 years
x = 18 - y
x = 18 - 3
x = 15 years
