SOLUTION: Leo works at the bagel shop after school and on Saturdays. He is paid $4 per hour after school and $5 per hour on Saturday. Last week Leo worked a total of 12 hours and made a tota

Algebra ->  Test -> SOLUTION: Leo works at the bagel shop after school and on Saturdays. He is paid $4 per hour after school and $5 per hour on Saturday. Last week Leo worked a total of 12 hours and made a tota      Log On


   

Question 729400: Leo works at the bagel shop after school and on Saturdays. He is paid $4 per hour after school and $5 per hour on Saturday. Last week Leo worked a total of 12 hours and made a total of $52.50. How many hours did he work after school?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = hours worked after school
Let +b+ = hours worked on Saturday
---------
given:
(1) +a+%2B+b+=+12+
(2) +4a+%2B+5b+=+52.5+
---------------------
(2) +40a+%2B+50b+=+525+
Multiply both sides of (1) by +40+
and subtract (1) from (2)
(2) +40a+%2B+50b+=+525+
(1) +-40a+-+40b+=+480+
+10b+=+45+
+b+=+4.5+
and
(1) +a+%2B+4.5+=+12+
(1) +a+=+7.5+
He worked 7.5 hours worked after school
He worked 4.5 hours worked on Saturday
check:
(2) +4a+%2B+5b+=+52.5+
(2) +4%2A7.5+%2B+5%2A4.5+=+52.5+
(2) +30+%2B+22.5+=+52.5+
(2) +52.5+=+52.5+
OK