3s+5s(s-3)+8=0

Solution for 3s+5s(s-3)+8=0 equation:

Simplifying
3s + 5s(s + -3) + 8 = 0

Reorder the terms:
3s + 5s(-3 + s) + 8 = 0
3s + (-3 * 5s + s * 5s) + 8 = 0
3s + (-15s + 5s2) + 8 = 0

Reorder the terms:
8 + 3s + -15s + 5s2 = 0

Combine like terms: 3s + -15s = -12s
8 + -12s + 5s2 = 0

Solving
8 + -12s + 5s2 = 0

Solving for variable 's'.

Begin completing the square.  Divide all terms by
5 the coefficient of the squared term: 

Divide each side by '5'.
1.6 + -2.4s + s2 = 0

Move the constant term to the right:

Add '-1.6' to each side of the equation.
1.6 + -2.4s + -1.6 + s2 = 0 + -1.6

Reorder the terms:
1.6 + -1.6 + -2.4s + s2 = 0 + -1.6

Combine like terms: 1.6 + -1.6 = 0.0
0.0 + -2.4s + s2 = 0 + -1.6
-2.4s + s2 = 0 + -1.6

Combine like terms: 0 + -1.6 = -1.6
-2.4s + s2 = -1.6

The s term is -2.4s.  Take half its coefficient (-1.2).
Square it (1.44) and add it to both sides.

Add '1.44' to each side of the equation.
-2.4s + 1.44 + s2 = -1.6 + 1.44

Reorder the terms:
1.44 + -2.4s + s2 = -1.6 + 1.44

Combine like terms: -1.6 + 1.44 = -0.16
1.44 + -2.4s + s2 = -0.16

Factor a perfect square on the left side:
(s + -1.2)(s + -1.2) = -0.16

Can't calculate square root of the right side.

The solution to this equation could not be determined.