SOLUTION: Question: Michelle's age is three years less than five time her daughter's age. In 11 years Michelle's age will be 7 years more than twice her daughter's age will be then. Ho

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Question 1037474: Question:
Michelle's age is three years less than five time her daughter's age. In 11 years Michelle's age will be 7 years more than twice her daughter's age will be then.
How old Michelle was 8 years ago?

Found 2 solutions by josmiceli, Vixiachase:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = Michelle's age now
Let +b+ = her daughter's age now
--------------------------------
(1) +a+=+5b+-+3+
(2) +a+%2B+11+=+2%2A%28+b+%2B+11+%29+%2B+7+
--------------------------------
Substitute (1) into (2)
(2) +5b+-+3+%2B+11+=+2%2A%28+b+%2B+11+%29+%2B+7+
(2) +5b+-+3+%2B+11+=+2b+%2B+22+%2B+7+
(2) +5b+%2B+8+=+2b+%2B+29+
(2) +3b+=+21+
(2) +b+=+7+
and
(1) +a+=+5b+-+3+
(1) +a+=+5%2A7+-+3+
(1) +a+=+35+-+3+
(1) +a+=+32+
-----------------
How old Michelle was 8 years ago?
+a+-+8+=+32+-+8+
+a+-+8+=+24+
----------------------------
Michelle was 24 yrs old 8 yrs ago
----------------------------
check:
(2) +a+%2B+11+=+2%2A%28+b+%2B+11+%29+%2B+7+
(2) +32+%2B+11+=+2%2A%28+7+%2B+11+%29+%2B+7+
(2) +43+=+2%2A18+%2B+7+
(2) +43+=+36+%2B+7+
(2) +43+=+43+
and
(1) +a+=+5b+-+3+
(1) +32+=+5%2A7+-+3+
(1) +32+=+35+-+3+
(1) +32+=+32+
OK

Answer by Vixiachase(22) About Me  (Show Source):