Question

Solve x^2 - 3x = -8.

Answer 1

Solve this quadratic equation like this :
First try to convert it in form ax^2+bx+c=0
where a,b,c are parameters(constant) and x is variable
So we do in this question take 8 to right hand side
we get
x^2-3x+8=0
Take the D the discriminant= (b^2-4*a*c)^1/2
=(-3^2-4*1*8)^1/2
=-23^1/2= \[\sqrt{-23}=i*\sqrt{23}\]
i is the value =\[\sqrt{-1}\]
Now we have 2 roots as it is quadratic as

r1=(-b+D)/4a and r2=(-b-D)/4a
so r1=(3+i* \[\sqrt{23}\])/4
and r2=(3-i* \[\sqrt{23}\])/4