Question 89972
x^2+x-2=0

the standard form of quadratic equation is 
ax^2+bx+c=0
comparing standard form with given equation we get
a=1; b=1 & c=-2

the standard solution is

Solution by SOLVE quadratic equation with variable
Quadratic equation  (in our case ) has the following solutons:



For these solutions to exist, the discriminant  should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=9 is greater than zero. That means that there are two solutions: .




Quadratic expression  can be factored:

Again, the answer is: 2, -1. Here's your graph:
 
 


by factorisation 
x^2+2x-x-2=0
x(x+2)-1(x+2)=0
(x-1)(x+2)=0
x=1
x=-2