Question

If you ask Megan how many dogs she has, she answers with a riddle: "Four-sevenths of my dogs plus 9." How many dogs does she have?

Answer 1

Explanation:

This is a simple system of equations problem, with our equation being:

`(4)/(7)x+9=x`

We know this as her dogs (x) is equal to 4/7 of her dogs (x) plus 9. Now all we must do is solve for x:

`(4)/(7)x+9=x\\\\(4)/(7)x=x-9\\\\(4)/(7)x=(7)/(7)x-9\\\\(-3)/(7)x=-9\\\\x=21`