ax^2+bx+c=0
The quadratic formula is
x=(-b+/-√(b^2-4ac))/2a
The part √(b^2-4ac) tells us how many solution we will get:
using -3x^2+x-4
√(1-4(-4)(-3))=√(1-36)=√-35 this is an impossible result since the inside of a square root has to be always greater or equal to zero. This means that the equation has no solutions.