Math help?

x^2 + 6x -.8 = 0
x
= [-b ± √(b² - 4ac)]/(2a)
= [-6 ± √(36 + 32)]/2
= -3 ± √17
= -7.1231056..., 1.1231056...

The solutions of ax² + bx + c = 0 are

x = [-b ± sqrt(b² - 4ac)]/(2a)

x²+6x-.8=0
x²+6x-4/5=0
a=1, b=6, c=-4/5

quadratic formula
x=(-6±√(36-4(-4/5)))/2
x=(-6±√(36+16/5))/2
x=(-6±√196/5)/2
x=(-6±14√(1/5))/2
x= -3±7/√5
x= -3±7/5•√5
x ~ 0.13, -6.13

x = [- b ± √ (b² - 4ac) ] / 2a
x = [- 6 ± √ (36 + 32) ] / 2
x = [- 6 ± √68 ] / 2
x = [- 6 ± 2√17 ] / 2
x = - 3 ± √17

a = 1
b = 6
c = -0.8

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

x = [-6 +/- sq root (36 + 3.2)] / (2)

x = [ -6 +/- sq root 39.2 ] / 2 <<< use a calculator

x = -6.13 and x = +0.13 <<< 2 answers

x² + 6x -8=0
x² + 6x +9=8+9
(x+3)² =17
x+3=√17 or x+3=-√17
x=-3+√17 or x+3=-3-√17

This equation is of form ax^2+bx+c
a = 1 b = 6 c = -0.8
x=[-b+/-sqrt(b^2-4ac)]/2a]
x=[-6 +/-sqrt(6^2-4(1)(-0.8)]/(2)(1)
discriminant is b^2-4ac =39.2
x=[-6 +√(39.2)] / (2)(1)
x=[-6 -√(39.2)] / (2)(1)

x=[-6+6.260990337] / 2
x=[-6-6.260990337] / 2
x= 0.1305 and -6.1305

a=1, b=6, and c=-0.8

-6 +/- [(6^2 - 4(1)(-0.8)]^0.5 all divided by 2(1)

x = .26/2 or -12.26/2 ==> 0.13 or -12.13

You give the answer in your question. That is simple math. If you have not mastered the basics, you should not be attempting to work with polynomial equations.