Question 278697
Hello, 
Let's get everything on one side of the = sign by subtracting 20. 
4x^2+11x-20 = 0
Now we can factor this to get:
(4x-5)(x+4)=0
X=-4
x=5/4
There we go. check out the answers to see if it works. 
Make sense?
RJ
There's a book I wrote that might help. 
www.math-unlock.com