SOLUTION: The sum of Sofia's age and Sonya's age is 65. Eleven years ago, Sonya was seven less than four times as old as Sofia. Find Sofia's age now.

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The sum of Sofia's age and Sonya's age is 65. Eleven years ago, Sonya was seven less than four times as old as Sofia. Find Sofia's age now.      Log On


   

Question 1163711: The sum of Sofia's age and Sonya's age is 65. Eleven years ago, Sonya was seven less than four times as old as Sofia. Find Sofia's age now.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
f, Sofia
n, Sonya
system%28f%2Bn=65%2Cn-11=4%28f-11%29-7%29

Question asks for Sofia's age. Substitute using n=65-f in the second equation and solve it for f.

highlight%28f=21%29

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
The sum of Sofia's age and Sonya's age is 65. Eleven years ago, Sonya was seven less than four times as old as Sofia. Find Sofia's age now.
Let Sofia's age be S

Then Sonya's is: 65 - S

We then get: 65 - S - 11 = 4(S - 11) - 7

54 - S = 4S - 44 - 7

- S - 4S = - 44 - 7 - 54

- 5S = - 105

Sofia, or