Question

SOMEONE HELP PLEASE! A lot of points!

The age of Mike's brother is 12 less than 4 times Mike's age. The sum of their ages is 28. Find the ages of Mike and his brother. State your answers as integer
Mike is (a) and his brother is [b]
I know the answer is A=8 and B= 20 but how do I get that answer?

Answer 1

First, you have to form simultaneous equation for both of their ages in yerms of a and b :

b = 4a - 12 -------- ( 1 )

a + b = 28 -------- ( 2 )

Next, you will have to solve it by substituting ( 1 ) into ( 2 ) :

a + (4a - 12) = 28

5a - 12 = 28

5a = 28 + 12

5a = 40

a = 8

Then, substitute a = 8 into ( 1 ) :

b = 4(8) - 12

b = 32 - 12

b = 20