A. Lisa is 15 years old and her father is 40. How many years ago was the father six times as old as Lisa?

B. Joel is one third the age of Bob. In 7 years the combined ages of the boys will be 58. How old is each boy now?

2 answers

A. Let x = years ago

6(15-x) = 40-x

Solve for x.

B. B = 3J

(B+7) +( J+7) = 68

Substitute 3J for B in second equation and solve for J. Insert that value into the first equation and solve for B. Check by inserting both values into the second equation.
A. 10 yearsc

B. 11 and 33