SOLUTION: Jack is 4 times as old as Lacy. 8 years from now the sum of their ages will be 76. How old are they now?

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Question 1034606: Jack is 4 times as old as Lacy. 8 years from now the sum of their ages will be 76. How old are they now?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = Jack's age now
Let +b+ = Lacy's age now
-----------------------
(1) +a+=+4b+
(2) +%28+a+%2B+8+%29+%2B+%28+b+%2B+8+%29+=+76+
----------------------------
Substitute (1) into (2)
(2) +%28+4b+%2B+8+%29+%2B+%28+b+%2B+8+%29+=+76+
(2) +5b+%2B+16+=+76+
(2) +5b+=+60+
(2) +b+=+12+
and
(1) +a+=+4b+
(1) +a+=+4%2A12+
(1) +a+=+48+
--------------------
Jack is 48 and Lacy is 12
--------------------------
check:
(2) +%28+a+%2B+8+%29+%2B+%28+b+%2B+8+%29+=+76+
(2) +%28+48+%2B+8+%29+%2B+%28+12+%2B+8+%29+=+76+
(2) +56+%2B+20+=+76+
(2) +76+=+76+
OK