SOLUTION: Can you please help me with this i do not understand this? Solve by factoring x^2 - 9x = -20 thank you julie

Algebra ->  Radicals -> SOLUTION: Can you please help me with this i do not understand this? Solve by factoring x^2 - 9x = -20 thank you julie      Log On


   

Question 118177: Can you please help me with this i do not understand this?
Solve by factoring
x^2 - 9x = -20
thank you
julie
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

x%5E2-9x=-20 Start with the given equation


x%5E2-9x%2B20=0 Add 20 to both sides.

%28x-5%29%28x-4%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-5=0 or x-4=0

x=5 or x=4 Now solve for x in each case


So our answer is
x=5 or x=4


Notice if we graph y=x%5E2-9x%2B20 we can see that the roots are x=5 and x=4 . So this visually verifies our answer.


+graph%28500%2C500%2C-10%2C10%2C-10%2C10%2C0%2C+x%5E2-9x%2B20%29+