X*X+7X=18

Solution for X*X+7X=18 equation:

Simplifying
X * X + 7X = 18

Multiply X * X
X2 + 7X = 18

Reorder the terms:
7X + X2 = 18

Solving
7X + X2 = 18

Solving for variable 'X'.

Reorder the terms:
-18 + 7X + X2 = 18 + -18

Combine like terms: 18 + -18 = 0
-18 + 7X + X2 = 0

Factor a trinomial.
(-9 + -1X)(2 + -1X) = 0

Subproblem 1
Set the factor '(-9 + -1X)' equal to zero and attempt to solve:

Simplifying
-9 + -1X = 0

Solving
-9 + -1X = 0

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

Add '9' to each side of the equation.
-9 + 9 + -1X = 0 + 9

Combine like terms: -9 + 9 = 0
0 + -1X = 0 + 9
-1X = 0 + 9

Combine like terms: 0 + 9 = 9
-1X = 9

Divide each side by '-1'.
X = -9

Simplifying
X = -9
Subproblem 2
Set the factor '(2 + -1X)' equal to zero and attempt to solve:

Simplifying
2 + -1X = 0

Solving
2 + -1X = 0

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

Add '-2' to each side of the equation.
2 + -2 + -1X = 0 + -2

Combine like terms: 2 + -2 = 0
0 + -1X = 0 + -2
-1X = 0 + -2

Combine like terms: 0 + -2 = -2
-1X = -2

Divide each side by '-1'.
X = 2

Simplifying
X = 2
Solution
X = {-9, 2}