SOLUTION: Please help me solve this equation: x^2-20x=125 We have to solve the equation to see what its roots/complex numbers are.

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Question 672609: Please help me solve this equation: x^2-20x=125
We have to solve the equation to see what its roots/complex numbers are.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-20x=125

x%5E2-20x-125=0

Use the quadratic formula to solve for x

x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F%282a%29

x+=+%28-%28-20%29%2B-sqrt%28%28-20%29%5E2-4%281%29%28-125%29%29%29%2F%282%281%29%29 Plug in a+=+1, b+=+-20, c+=+-125

x+=+%2820%2B-sqrt%28400-%28-500%29%29%29%2F%282%29

x+=+%2820%2B-sqrt%28400%2B500%29%29%2F%282%29

x+=+%2820%2B-sqrt%28900%29%29%2F2

x+=+%2820%2Bsqrt%28900%29%29%2F2 or x+=+%2820-sqrt%28900%29%29%2F2

x+=+%2820%2B30%29%2F2 or x+=+%2820-30%29%2F2

x+=+50%2F2 or x+=+-10%2F2

x+=+25 or x+=+-5

So the two roots/solutions are x+=+25 or x+=+-5