SOLUTION: The age of a father is triple the son. 5 years later the product of their ages will be 1000. Find their present ages.

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Question 956013: The age of a father is triple the son. 5 years later the product of their ages will be 1000. Find their present ages.
Answer by macston(5194)   (Show Source): You can put this solution on YOUR website!
F=father's age; S=son's age

Substitute for F.

Subtract 1000 from each side.
Solved by pluggable solver: SOLVE quadratic equation with variable
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=12100 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 15, -21.6666666666667. Here's your graph:

So S=15 ANSWER 1: The son is 15 years old.
F=3S=3(15yrs)=45yrs ANSWER 2: The father is 45 years old.
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