SOLUTION: x2 - 3x =4

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Question 117858: x2 - 3x =4
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E2-3x=4 Start with the given equation


x%5E2-3x-4=0 Subtract 4 from both sides


%28x-4%29%28x%2B1%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-4=0 or x%2B1=0

x=4 or x=-1 Now solve for x in each case


So our answer is
x=4 or x=-1


Notice if we graph y=x%5E2-3x-4 we can see that the roots are x=4 and x=-1 . So this visually verifies our answer.


+graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C0%2C+x%5E2-3x-4%29+