SOLUTION: X square = 5x + 36 how will i know the solution...can you give it to me? thanks

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Question 55656: X square = 5x + 36
how will i know the solution...can you give it to me?
thanks
Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2=5x%2B36 Set the problem =0
x%5E2-5x-36=5x-5x%2B36-36
x%5E2-5x-36=0 Factor.
(x___)(x___) Two numbers that multiply to give you -36, but add to give -5 are -9 and +4, -9*4=-36 and -9+4=-5
(x-9)(x+4)=0 Use the zero product property and set each parenthesis=0
x-9=0
x=9
and
x+4=0
x=-4
x={-4,9}
Check
%28-4%29%5E2=5%28-4%29%2B36
16=-20%2B36
16=16 -4 checks out.
%289%29%5E2=5%289%29%2B36
81=45%2B36
81=81 9 checks out also, we're right!!!
Happy Calculating!!!