SOLUTION: if a number is increased by its square the result is 72.find the number.

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Question 36832: if a number is increased by its square the result is 72.find the number.
Answer by vidhyak(98) About Me  (Show Source):
You can put this solution on YOUR website!
Let the number be x and square of the number be x^2
x + x^2 = 72
x^2 +x -72 = 0
x^2 +9x -8x -72 = 0
x(x+9) -8(x+9) =0
(x-8)(x+9) = 0
x = 8, -9
Verify
x + x^2
8 +8^2
8 + 64 = 72

x + x^2
(-9) +(-9)^2
-9 + 81 = 72