(18+2x)(x-4)=84

Simple and best practice solution for (18+2x)(x-4)=84 equation. Check how easy it is, and learn it for the future. Our solution is simple, and easy to understand, so don`t hesitate to use it as a solution of your homework.

If it's not what You are looking for type in the equation solver your own equation and let us solve it.

Solution for (18+2x)(x-4)=84 equation: 


Simplifying
(18 + 2x)(x + -4) = 84

Reorder the terms:
(18 + 2x)(-4 + x) = 84

Multiply (18 + 2x) * (-4 + x)
(18(-4 + x) + 2x * (-4 + x)) = 84
((-4 * 18 + x * 18) + 2x * (-4 + x)) = 84
((-72 + 18x) + 2x * (-4 + x)) = 84
(-72 + 18x + (-4 * 2x + x * 2x)) = 84
(-72 + 18x + (-8x + 2x2)) = 84

Combine like terms: 18x + -8x = 10x
(-72 + 10x + 2x2) = 84

Solving
-72 + 10x + 2x2 = 84

Solving for variable 'x'.

Reorder the terms:
-72 + -84 + 10x + 2x2 = 84 + -84

Combine like terms: -72 + -84 = -156
-156 + 10x + 2x2 = 84 + -84

Combine like terms: 84 + -84 = 0
-156 + 10x + 2x2 = 0

Factor out the Greatest Common Factor (GCF), '2'.
2(-78 + 5x + x2) = 0

Ignore the factor 2.

Subproblem 1
Set the factor '(-78 + 5x + x2)' equal to zero and attempt to solve:

Simplifying
-78 + 5x + x2 = 0

Solving
-78 + 5x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '78' to each side of the equation.
-78 + 5x + 78 + x2 = 0 + 78

Reorder the terms:
-78 + 78 + 5x + x2 = 0 + 78

Combine like terms: -78 + 78 = 0
0 + 5x + x2 = 0 + 78
5x + x2 = 0 + 78

Combine like terms: 0 + 78 = 78
5x + x2 = 78

The x term is 5x.  Take half its coefficient (2.5).
Square it (6.25) and add it to both sides.

Add '6.25' to each side of the equation.
5x + 6.25 + x2 = 78 + 6.25

Reorder the terms:
6.25 + 5x + x2 = 78 + 6.25

Combine like terms: 78 + 6.25 = 84.25
6.25 + 5x + x2 = 84.25

Factor a perfect square on the left side:
(x + 2.5)(x + 2.5) = 84.25

Calculate the square root of the right side: 9.178779875

Break this problem into two subproblems by setting 
(x + 2.5) equal to 9.178779875 and -9.178779875.


Subproblem 1
x + 2.5 = 9.178779875

Simplifying
x + 2.5 = 9.178779875

Reorder the terms:
2.5 + x = 9.178779875

Solving
2.5 + x = 9.178779875

Solving for variable 'x'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + x = 9.178779875 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + x = 9.178779875 + -2.5
x = 9.178779875 + -2.5

Combine like terms: 9.178779875 + -2.5 = 6.678779875
x = 6.678779875

Simplifying
x = 6.678779875


Subproblem 2
x + 2.5 = -9.178779875

Simplifying
x + 2.5 = -9.178779875

Reorder the terms:
2.5 + x = -9.178779875

Solving
2.5 + x = -9.178779875

Solving for variable 'x'.

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

Add '-2.5' to each side of the equation.
2.5 + -2.5 + x = -9.178779875 + -2.5

Combine like terms: 2.5 + -2.5 = 0.0
0.0 + x = -9.178779875 + -2.5
x = -9.178779875 + -2.5

Combine like terms: -9.178779875 + -2.5 = -11.678779875
x = -11.678779875

Simplifying
x = -11.678779875


Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {6.678779875, -11.678779875}
Solution
x = {6.678779875, -11.678779875}

See similar equations:

| .10x+.15(90000-x)=10000 | | 6x-5x=6.6+1.1 | | 5(6x-3-(6x+1))=0 | | W^2+2w-36=0 | | -3x^2+15=0 | | 7x+7=5-3x+6 | | -7t^2+20t+3=0 | | -2=x/5-8 | | y=mx+b*m | | -37=-13+4m | | 2t(t-4)=-3 | | (-x*2)4+12=44-48 | | -2-4n=6 | | 6b^2-23b+15=0 | | 4x-2x-7=15 | | 3(x+2)=5-2(x+3) | | 70=145e-0.092t | | -20m-24=76 | | 9=3+3n | | 2.9w+11.4=2.6-0.2y | | 48=x-0.04x | | 8-2x+3=3 | | 2n+-3=17 | | 3M-M+1=5 | | 42+3=15 | | 4y-4=3x | | x-.20=220 | | 3v+7u= | | 495=x(x+2)5 | | 3M-M+1=8 | | 1.3(2.2m-5.1)+2=3.2(1.6m-4) | | 7*-7+(6*9-6)= |

Equations solver categories