SOLUTION: Solve each equation by using the method for your choice. Find exact solutions. 8. x^2+8x=0 Thanks for your help!

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Question 181939This question is from textbook Algebra2
: Solve each equation by using the method for your choice. Find exact solutions.
8. x^2+8x=0
Thanks for your help! This question is from textbook Algebra2

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
I'm going to use the quadratic formula:


x%5E2%2B8x=0 Start with the given equation.


x%5E2%2B8x%2B0=0 Add 0 to the left side (this does NOT change the equation)


Notice we have a quadratic equation in the form of ax%5E2%2Bbx%2Bc where a=1, b=8, and c=0


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-%288%29+%2B-+sqrt%28+%288%29%5E2-4%281%29%280%29+%29%29%2F%282%281%29%29 Plug in a=1, b=8, and c=0


x+=+%28-8+%2B-+sqrt%28+64-4%281%29%280%29+%29%29%2F%282%281%29%29 Square 8 to get 64.


x+=+%28-8+%2B-+sqrt%28+64-0+%29%29%2F%282%281%29%29 Multiply 4%281%29%280%29 to get 0


x+=+%28-8+%2B-+sqrt%28+64+%29%29%2F%282%281%29%29 Subtract 0 from 64 to get 64


x+=+%28-8+%2B-+sqrt%28+64+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-8+%2B-+8%29%2F%282%29 Take the square root of 64 to get 8.


x+=+%28-8+%2B+8%29%2F%282%29 or x+=+%28-8+-+8%29%2F%282%29 Break up the expression.


x+=+%280%29%2F%282%29 or x+=++%28-16%29%2F%282%29 Combine like terms.


x+=+0 or x+=+-8 Simplify.


So the answers are x+=+0 or x+=+-8