SOLUTION: Please help me solve this equation. x(x-20)=-100

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Question 131639: Please help me solve this equation.
x(x-20)=-100
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x%28x-20%29=-100 Start with the given equation


x%5E2-20x=-100 Distribute


x%5E2-20x%2B100=0 Add 100 to both sides.


%28x-10%29%28x-10%29=0 Factor the left side (note: if you need help with factoring, check out this solver)



Now set each factor equal to zero:
x-10=0 or x-10=0

x=10 or x=10 Now solve for x in each case


Since we have a repeating answer, our only answer is x=10

Notice if we graph y=x%5E2-20x%2B100 we can see that the only root is x=10. So this visually verifies our answer.


+graph%28500%2C500%2C-5%2C15%2C-10%2C10%2C0%2C+x%5E2-20x%2B100%29+