(x^2)-(7x)-(8)=0

Solution for (x^2)-(7x)-(8)=0 equation:

Simplifying
(x2) + -1(7x) + -1(8) = 0
x2 + -1(7x) + -1(8) = 0

Remove parenthesis around (7x)
x2 + -1 * 7x + -1(8) = 0

Multiply -1 * 7
x2 + -7x + -1(8) = 0

Multiply -1 * 8
x2 + -7x + -8 = 0

Reorder the terms:
-8 + -7x + x2 = 0

Solving
-8 + -7x + x2 = 0

Solving for variable 'x'.

Factor a trinomial.
(-1 + -1x)(8 + -1x) = 0

Subproblem 1
Set the factor '(-1 + -1x)' equal to zero and attempt to solve:

Simplifying
-1 + -1x = 0

Solving
-1 + -1x = 0

Move all terms containing x to the left, all other terms to the right.

Add '1' to each side of the equation.
-1 + 1 + -1x = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -1x = 0 + 1
-1x = 0 + 1

Combine like terms: 0 + 1 = 1
-1x = 1

Divide each side by '-1'.
x = -1

Simplifying
x = -1
Subproblem 2
Set the factor '(8 + -1x)' equal to zero and attempt to solve:

Simplifying
8 + -1x = 0

Solving
8 + -1x = 0

Move all terms containing x to the left, all other terms to the right.

Add '-8' to each side of the equation.
8 + -8 + -1x = 0 + -8

Combine like terms: 8 + -8 = 0
0 + -1x = 0 + -8
-1x = 0 + -8

Combine like terms: 0 + -8 = -8
-1x = -8

Divide each side by '-1'.
x = 8

Simplifying
x = 8
Solution
x = {-1, 8}