SOLUTION: Jack is 24 years older than Mary is now. Four years ago, he was seven times as old as Mary was then. How old is Jack now?

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Question 261387: Jack is 24 years older than Mary is now. Four years ago, he was seven times as old as Mary was then. How old is Jack now?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let j = Jack's age now
Let m = Mary's age now
given:
(1) j+=+m+%2B+24
(2) j+-+4+=+7%2A%28m+-+4%29
----------------------------
From (1),
(1) j+-+m+=+24
From (2),
(2) j+-+4+=+7m+-+28
(2) j+-+7m+=+-24
(2) -j+%2B+7m+=+24
Now add (1) and (2)
j+-+m+=+24
-j+%2B+7m+=+24
6m+=+48
m+=+8
And, since
j+-+m+=+24
j+-+8+=+24
j+=+32
Jack is 32 now
check answer:
(2) j+-+4+=+7%2A%28m+-+4%29
32+-+4+=+7%2A%288+-+4%29
28+=+7%2A4
28+=+28
OK