If 5x^2 - 3x-4=0, then what are the values of x?

This will not factor so you can use the quadratic formula

x = [ - (-3) + / - sqrt (9 - 4*5*-4) / 10

= (3 + / - sqrt 89) / 10

= 3 + 9.434 / 10 or 3 - 9.434 / 10

= 1.24, - 0.64 to the nearest hundredth