SOLUTION: ali's father was five times as old as Ali 7 1/2 years ago.After 7 1/2 years father will be twice as old as ALI .what are their present ages? a,12 1/2,32 1/2 b,5,25 c,12,32 d

Algebra ->  Proportions  -> Lessons -> SOLUTION: ali's father was five times as old as Ali 7 1/2 years ago.After 7 1/2 years father will be twice as old as ALI .what are their present ages? a,12 1/2,32 1/2 b,5,25 c,12,32 d      Log On


   

Question 997076: ali's father was five times as old as Ali 7 1/2 years ago.After 7 1/2 years father will be twice as old as ALI .what are their present ages?
a,12 1/2,32 1/2 b,5,25 c,12,32 d,5 1/2,25 1/2
Found 2 solutions by mananth, josgarithmetic:
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
7.5 years ago
ali -----x
father 5x
after 7.5 years
ali ---x+15
father 5x+15
2(x+15) =5x+15
2x+30 = 5x+15
3x =15
x=5
Ali present age = 5 +7.5 = 12.5 years
father's age =( 5 * 5)+7.5 = 32.5 years

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
x, Ali's age
y, Father's age

system%28y-7%261%2F2=5%28x-7%261%2F2%29%2Cy%2B7%261%2F2=2%28x%2B7%261%2F2%29%29

system%28y-7%261%2F2=5x-37%261%2F2%2Cy%2B7%261%2F2=2x%2B15%29

%28y-7%261%2F2%29-%28y%2B7%261%2F2%29=%285x-37%261%2F2%29-%282x%2B15%29---------obviously using elimination method; you finish this.