SOLUTION: please help me solve this: A father is four times as old as his son. In six years time,their combined ages will be 57. How old is the father now?

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Question 342360: please help me solve this: A father is four times as old as his son. In six years time,their combined ages will be 57. How old is the father now?
Found 2 solutions by Fombitz, MathTherapy:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Let the Father's age be F, the son's S.
In 6 years their ages are F%2B6 and S%2B6.
1.F=4S
.
.
.
%28F%2B6%29%2B%28S%2B6%29=57
F%2BS%2B12=57
2.F%2BS=45
Substitute eq. 1 into eq. 2,
4S%2BS=45
5S=45
highlight%28S=9%29years old
Then from eq. 1,
F=4%289%29
highlight%28F=36%29 years old

Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!
please help me solve this: A father is four times as old as his son. In six years time,their combined ages will be 57. How old is the father now?

Let father's age be F years

Since the father is four times as old as the son, then the son's age is 1%2F4 the father's age, or %281%2F4%29F years

In six year's time, the father will be (F + 6) years-old, and the son: %281%2F4%29F+%2B+6

Also, since in 6 year's time, their combined ages will be 57, then we'll have:

F+%2B+6+%2B+%281%2F4%29F+%2B+6+=+57

Multiplying the equation by it's LCD, 4, we get:

4F + 24 + F + 24 = 228

5F + 48 = 228

5F = 228 - 48

5F = 180

F, or father's age is: 180%2F5 or highlight_green%2836%29 years.