Question

Solve the given quadratic equations
x^2 + x -2 = 0
Its challenging questions

Answer 1

Use the following formula:  
x= {-b(√b²-4ac)}/2a
where a is 1, b is 1 and c is -2. 

therefore, x= {-1+-(plus,minus)√1²-4*1*(-2)}÷2*1
∴x= (-1+-√1+8)÷2
= (-1+3)÷2 
OR 
=(-1-3)÷2

⇒x=2/2 OR -4/2 
∴X=1 OR X= -2.

Hope this helps.

EDIT:
You can also do it as

x²+x-2=0
⇒x²+2x-x-2=0
⇒x(x+2)-1(x+2)=0
⇒(x-1)(x+2)=0
⇒x-1=0 OR x+2=0
∴x=1 OR x= -2.