Question 1202166
<br>
Sue is three times as old as Michelle.<br>
Starting from there...
let x = Michelle's age now
then 3x = Sue's age now  (she is now three times as old as Michelle)<br>
10 years ago she was seven times as old as Michelle was.<br>
From our starting point above, we need expressions for their ages 10 years ago:
x-10 = Michelle's age 10 years ago
3x-10 = Sue's age 10 years ago<br>
And now, using those expressions, write and solve an equation that says Sue's age 10 years ago was seven times Michelle's age 10 years ago:<br>
3x-10 = 7(x-10)
3x-10 = 7x-70
60 = 4x
x = 15<br>
How old is Sue now?:<br>
ANSWER: Sue's age now is 3x = 3(15) = 45<br>