Question

A China cup and saucer cost 12$. The cup on its own cost 3$ more than the saucer. Form an eqaution for s and solve it. Find the cost of the cup

Answer 1

If the cup = S + 3
and the
saucer = S
then


(S + 3) + S = 12
2s + 3 = 12
2s = 9
s = 4.50

So by itself the saucer costs $4.50. To find the cost of the cup look to the beginning of the problem where we learned that

Cup = S + 3
cup = 4.50 + 3
cup = 7.50

So the saucer is $4.50 and the cup is $7.50...

4.50 + 7.50 = $12.00

It checks!