SOLUTION: brian is twice his daughter's age plus 19 years. In 5 years Brian will be three times as old as she is. What is Brian's current age?

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Question 1054924: brian is twice his daughter's age plus 19 years. In 5 years Brian will be three times as old as she is. What is Brian's current age?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = Brian's age now
Let +b+ = his daughter's age now
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(1) +a+=+2b+%2B+19+
(2) +a+%2B+5+=+3%2A%28+b+%2B+5+%29+
--------------------------
(2) +a+%2B+5+=+3b+%2B+15+
(2) +a+-+3b+=+10+
and
(1) +a+-+2b+=+19+
--------------------------
Subtract (2) from (1)
(1) +a+-+2b+=+19+
(2) +-a+%2B+3b+=+-10+
-----------------------
+b+=+9+
and
(1) +a+=+2b+%2B+19+
(1) +a+=+2%2A9+%2B+19+
(1) +a+=+18+%2B+19+
(1) +a+=+37+
Brian is 37
-----------------------
check:
(2) +a+%2B+5+=+3%2A%28+b+%2B+5+%29+
(2) +37+%2B+5+=+3%2A%28+9+%2B+5+%29+
(2) +42+=+3%2A14+
(2) +42+=+42+
OK