SOLUTION: David's dad is twice his age and five more, the sum of their age is 71. What are their ages? Have taken 71 minus 5 divided by 2 then divided by 2 again. I have tried several di

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: David's dad is twice his age and five more, the sum of their age is 71. What are their ages? Have taken 71 minus 5 divided by 2 then divided by 2 again. I have tried several di      Log On


   

Question 1092658: David's dad is twice his age and five more, the sum of their age is 71. What are their ages?
Have taken 71 minus 5 divided by 2 then divided by 2 again. I have tried several different ways of doing like the one shower but when I add back up I don't get 71.
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
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David's dad is twice his age and five more, the sum of their age is 71.
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x, David
y, Dad

system%28y=2x%2B5%2Cx%2By=71%29
-
x%2B2x%2B5=71 through simply substituting;
3x%2B5=71
3x=71-5
3x=66
highlight%28x=22%29--------David's age
y=2%2A22%2B5
highlight%28y=49%29-------Dad's age