SOLUTION: The sum of a square of a positive number and the square of 3 more than a number is 45. what is the number?

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Question 965417: The sum of a square of a positive number and the square of 3 more than a number is 45. what is the number?
Found 2 solutions by t0hierry, macston:
Answer by t0hierry(194) About Me  (Show Source):
You can put this solution on YOUR website!
x^2 + (3 + x)^2 = 45
2x^2 + 81 + 6x = 45
2x^2 + 6x = 36
x^2 + 3x = 18
x = 3

Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
.
x%5E2%2B%28x%2B3%29%5E2=45
x%5E2%2Bx%5E2%2B6x%2B9=45%29 Subtract 45 from each side.
2x%5E2%2B6x-36=0 Divide by 2
x%5E2%2B3x-18=0
%28x%2B6%29%28x-3%29=0
x%2B6=0 or x-3=0
x=-6 or x=3
ANSWER: The positive number is 3.
.
CHECK:
x%5E2%2B%28x%2B3%29%5E2=45
3%5E2%2B%283%2B3%29%5E2=45
9%2B6%5E2=45
9%2B36=45
45=45