Today Rebecca, who is 34 years old

Nicola Key

You can back solve by by substituting the answers choices and till you get the one that works out.

Jun 11, 2017 • Comment

Nicholas Dureault

Let 'x' equal the amount of years to pass.

so we get:

34 + x
-------- = 8 + x
2

Since we are looking for Rebecca to be twice her daughters age, we need to divide her future age (current age + 'x') by '2' in order for the equation to balance.
(This is where I originally was hung up in creating the equation, I didn't know what to do with the "twice her daughter's age" part).

We can move the denominator '2' by multiplying both sides by 2 and you get:
34 + x = 2(8 + x)

Simplify:
34 + x = 16 + 2x

move the x's over to one side and the numbers over to the other:
34 - 16 = 2x - x

Simplify and solve:
18 = x

Dec 19, 2015 • Comment