SOLUTION: scott is 4 times older than bethany. in six years from now scott will only be 3 times older than bethany. Write down two equations to describe the relationship between their ages.

Let S be the Scott's present age and B be the Bethany's present age.

Then you have this system of two equations

S = 4B              (1)
S + 6 = 3*(B+6)     (2)

From (1), substitute the expression S = 4B into equation (2). You will get

4B + 6 = 3*(B+6),

4B + 6 = 3B + 18  ---->  B = 12.

Thus Bethany is 12 years old now.

Then Scott is 12*4 = 48 years old now.


You can easily check that this solution satisfies the condition.