SOLUTION: Age Practice Problem The sum of the ages of Blake and Mackenzie is 68 years. 8 years ago, Blake's age was 3 times Mackenzie's age. How old is Blake now?

Algebra ->  Linear-equations -> SOLUTION: Age Practice Problem The sum of the ages of Blake and Mackenzie is 68 years. 8 years ago, Blake's age was 3 times Mackenzie's age. How old is Blake now?      Log On


   

Question 1175129: Age Practice Problem
The sum of the ages of Blake and Mackenzie is 68 years. 8 years ago, Blake's age was 3 times Mackenzie's age. How old is Blake now?
Answer by MathLover1(20850) About Me  (Show Source):
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let Blake ‘s age be B and Mackenzie's age M
if the sum of the ages of Blake and Mackenzie is 68 years, we have
B%2BM=68....solve for B
B=68-M....eq.1
if 8 years ago Blake's age was 3 times Mackenzie's age, we have
B-8=3%28M-8%29....eq.2......substitute B
68-M-8=3M-24
68%2B24-8=3M%2BM
84=4M
84%2F4=M
M=21
go to
B=68-M....eq.1....substitute M
B=68-21
B=47
answer: Blake is 47 years old now