SOLUTION: I Need the Solutions Of x^2+9x+20=0

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Question 592287: I Need the Solutions Of x^2+9x+20=0
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2%2B9x%2B20=0 Start with the given equation.


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=9, and c=20


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%289%29+%2B-+sqrt%28+%289%29%5E2-4%281%29%2820%29+%29%29%2F%282%281%29%29 Plug in a=1, b=9, and c=20


x+=+%28-9+%2B-+sqrt%28+81-4%281%29%2820%29+%29%29%2F%282%281%29%29 Square 9 to get 81.


x+=+%28-9+%2B-+sqrt%28+81-80+%29%29%2F%282%281%29%29 Multiply 4%281%29%2820%29 to get 80


x+=+%28-9+%2B-+sqrt%28+1+%29%29%2F%282%281%29%29 Subtract 80 from 81 to get 1


x+=+%28-9+%2B-+sqrt%28+1+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-9+%2B-+1%29%2F%282%29 Take the square root of 1 to get 1.


x+=+%28-9+%2B+1%29%2F%282%29 or x+=+%28-9+-+1%29%2F%282%29 Break up the expression.


x+=+%28-8%29%2F%282%29 or x+=++%28-10%29%2F%282%29 Combine like terms.


x+=+-4 or x+=+-5 Simplify.


So the answers are x+=+-4 or x+=+-5