Thursday, August 22, 2013

the sum of positive number and its square is 72.Find the number

x+x^2=72 
x%5E2%2Bx-72=0 
-8*9=-72 and -8+9=1 
so... 
x%5E2%2Bx-72=%0D%0A%28x-9%29%28x%2B8%29=0 


checking...
-8+64 is not 72 
but 
9+63=72 
so it is 9
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