SOLUTION: Please help me with this problem.Solve: x^2-3x-40=0

Algebra ->  Equations -> SOLUTION: Please help me with this problem.Solve: x^2-3x-40=0      Log On


   

Question 110995: Please help me with this problem.Solve: x^2-3x-40=0
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2-3x-40=0

%28x-8%29%28x%2B5%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-8=0 or x%2B5=0

x=8 or x=-5 Now solve for x in each case


So our solutions are x=8 or x=-5


Notice if we graph y=x%5E2-3x-40 we get

+graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C+x%5E2-3x-40%29+

and we can see that the graph has roots at x=8 and x=-5, so this verifies our answer.