SOLUTION: I do not understand how to do the Quadratic Equation r2(squared) + 10r + 9 =0

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Question 8347: I do not understand how to do the Quadratic Equation r2(squared) + 10r + 9 =0
Answer by bonster(299) About Me  (Show Source):
You can put this solution on YOUR website!
r%5E2+%2B+10r+%2B+9 =0
what two numbers can you multiply to get the product 9, yet at the same time, has the sum of 10? 9 and 1

(r+1)(r+9)=0

When r+1=0
r=-1

When r+9=0
r=-9