Math Problem x4

Question

Noah is 39 years old. Erica is 18 years old. How many years ago was Noah's age 4 times Erica's age?

Answer 1

Given information:

Noel is 39 years old

Erica is 18

Requested Information

The number of previous years that Noel's age then was 4 times Erica's age at that time

Let X = number of past years

Then 39 - x = 4 (18-x)

39 - x = 72 - 4x

Combining like terms gives

-3X = 33

x = 11

Therefore 11 years ago

Noah was 28 and Erica was 7

28 = 4 X 7 Check

Answer 2

N-x = 4(E-x)

39-x = 4(18-x) = 72-4x

3x = 72-39 = 33

x = 33/3 = 11 years ago Noah was 4 times Erica's age

39-11 = 4(18-11)

28 = 4(7)