help with using the quadratic formula

Question

how do you use the quadratic formula to solve z^2+16z+54=0?

Answer 1

A=1 B=16 z=54

z = [-16 +or- sqrt ( 16^2 - 4(1)(54) ) ]/2

= [ -16 +or- sqrt( 256 - 216)]/2

= [ -16 +or- sqrt(40)]/2

= [ -16 +or- 2*sqrt(10)]/2

= -8 +or- sqrt(10)