Question

The sum of 4 times Lisa's age and 7 times Olivia's age is 169. Olivia is 1 year more than

twice as old as Lisa. Find each of their ages.

Answer 1

Answers:

Lisa is currently 9 years old

Olivia is currently 19 years old

==================================================

Step-by-step explanation:

L = Lisa's current age

2L+1 = Olivia's current age

This is because the 2L represents being twice as old as Lisa, then we add on an extra year.

Then we refer to the first sentence:

`\text{The sum of 4 times Lisa's age and 7 times Olivia's age is 169}`

to form this equation

4*(Lisa's age) + 7*(Olivia's age) = 169

4L + 7(2L+1) = 169

-------------------

Let's solve for L

4L + 7(2L+1) = 169

4L + 14L + 7 = 169

18L + 7 = 169

18L = 169-7

18L = 162

L = 9

Lisa is currently 9 years old.

That leads to,

2L+1 = 2*9+1 = 18+1 = 19

Olivia is currently 19 years old.

-----------------

Check:

4*(Lisa's age) + 7*(Olivia's age) = 169

4*9 + 7*19 = 169

36 + 133 = 169

169 = 169

The answers are confirmed.