SOLUTION: Mary's age is three times Jack's, plus 5 more. The sum of those ages is 65. What are their ages?

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Question 1078244: Mary's age is three times Jack's, plus 5 more. The sum of those ages is 65. What are their ages?
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
m Mary
j Jack

The description transformed into equations:
system%28m=3j%2B5%2Cm%2Bj=65%29


Using substitution:
%283j%2B5%29%2Bj=65

Solve for j, first.
3j%2B5%2Bj=65
3j%2Bj%2B5=65
4j=60
j=60%2F4
highlight%28j=15%29

Evaluate m.
m=3%2A15%2B5
m=45%2B5
highlight%28m=50%29
OR
m%2Bj=65
m=65-j
m=65-15
m=50


Mary is 50 and Jack is 15.