SOLUTION: Peter is 3 years older than his brother. The product of their ages is 270. Find Peter's age. Show the solutions

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Question 470226: Peter is 3 years older than his brother. The product of their ages is 270. Find Peter's age.
Show the solutions
Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
Let x is Peter's age
Then his brother is x-3 years old.
The product of their ages is x%28x-3%29=270
x%5E2-3x-270=0
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-3%29+%2B-+sqrt%28+%28-3%29%5E2-4%2A1%2A%28-270%29+%29%29%2F%282%2A1%29+
x+=+%283+%2B-+sqrt%28+1089+%29%29%2F2+
x1=%283-33%29%2F2=-15%3C0 extraneous root
x2=%283%2B33%29%2F2=36%2F2=18 is Peter's age
Answer: Peter is 18 years old