Given the equation below, which of the following shows the quadratic formula correctly applied? x2+5x-8=0

This is the concept of quadratic equations, to find out if the expression is correctly applied we solve the equation given using the quadratic formula;

x=[-b+/-sqrt[b^2-4ac]] / (2a)

Given the equation x^2+5x-8=0

then, a=1, b=5 and c=-8

Applying the formula we get:

x=[-5+/-sqrt (5^2-4*1 * (-8)) ] / (2*1)

x=[-5+/-sqrt (25+32) ]/2

x=[-5+/-sqrt57]2

The answer is:

x=[-5+/-sqrt57]/2