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!
