SOLUTION: Help me to resolve the quadratic equation: x²+3x=18

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Question 908526: Help me to resolve the quadratic equation: x²+3x=18
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Can you form a trinomial and then factor it?

x%5E2%2B3x%2B%28-18%29=18%2B%28-18%29
x%5E2%2B3x-18=0

What can you find for %28x%2Ba%29%28x%2Bb%29=x%5E2%2Bax%2Bab%2Bab=x%5E2%2B%28a%2Bb%29x%2Bab
and you want x%5E2%2B%28a%2Bb%29x%2Bab=x%5E2%2B3x-18.

What are the numbers, a and b, so that a%2Bb=3 and ab=-18?