SOLUTION: Sally is twice as old as Fred four years ago Sally was three times as old as Fred how old is Sally and Fred now

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Question 1031377: Sally is twice as old as Fred four years ago Sally was three times as old as Fred how old is Sally and Fred now
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +s+ = Sally's age now
Let +f+ = Fred's age now
------------------------
(1) +s+=+2f+
(2) +s+-+4+=+3%2A%28+f+-+4+%29+
------------------------
(2) +s+-+4+=+3f+-+12+
(2) +3f+=+s+%2B+8+
Plug (1) into (2)
(2) +3f+=+2f+%2B+8+
(2) +f+=+8+
and
(1) +s+=+2f+
(1) +s+=+2%2A8+
(1) +s+=+16+
---------------------
Sally is 16 and Fred is 8
---------------------
check:
(2) +s+-+4+=+3%2A%28+f+-+4+%29+
(2) +16+-+4+=+3%2A%28+8+-+4+%29+
(2) +12+=+3%2A4+
(2) +12+=+12+
OK