x^2+28x-84=0

Simple and best practice solution for x^2+28x-84=0 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 x^2+28x-84=0 equation:


Simplifying
x2 + 28x + -84 = 0

Reorder the terms:
-84 + 28x + x2 = 0

Solving
-84 + 28x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '84' to each side of the equation.
-84 + 28x + 84 + x2 = 0 + 84

Reorder the terms:
-84 + 84 + 28x + x2 = 0 + 84

Combine like terms: -84 + 84 = 0
0 + 28x + x2 = 0 + 84
28x + x2 = 0 + 84

Combine like terms: 0 + 84 = 84
28x + x2 = 84

The x term is 28x.  Take half its coefficient (14).
Square it (196) and add it to both sides.

Add '196' to each side of the equation.
28x + 196 + x2 = 84 + 196

Reorder the terms:
196 + 28x + x2 = 84 + 196

Combine like terms: 84 + 196 = 280
196 + 28x + x2 = 280

Factor a perfect square on the left side:
(x + 14)(x + 14) = 280

Calculate the square root of the right side: 16.733200531

Break this problem into two subproblems by setting 
(x + 14) equal to 16.733200531 and -16.733200531.

Subproblem 1

x + 14 = 16.733200531 Simplifying x + 14 = 16.733200531 Reorder the terms: 14 + x = 16.733200531 Solving 14 + x = 16.733200531 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-14' to each side of the equation. 14 + -14 + x = 16.733200531 + -14 Combine like terms: 14 + -14 = 0 0 + x = 16.733200531 + -14 x = 16.733200531 + -14 Combine like terms: 16.733200531 + -14 = 2.733200531 x = 2.733200531 Simplifying x = 2.733200531

Subproblem 2

x + 14 = -16.733200531 Simplifying x + 14 = -16.733200531 Reorder the terms: 14 + x = -16.733200531 Solving 14 + x = -16.733200531 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-14' to each side of the equation. 14 + -14 + x = -16.733200531 + -14 Combine like terms: 14 + -14 = 0 0 + x = -16.733200531 + -14 x = -16.733200531 + -14 Combine like terms: -16.733200531 + -14 = -30.733200531 x = -30.733200531 Simplifying x = -30.733200531

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.733200531, -30.733200531}

See similar equations:

| (3x+4)+(-4x+1)= | | N=Z/s | | 3w-27= | | 3x^2-46=2 | | 8=5i^2 | | 4xsquared-17x+13=0 | | 2x-30=90 | | 4w=5t-3w-t | | 7x+9-9x=17-18x+16x-8 | | N+n+15=70 | | x/-1/2=5/6 | | a+4a=2 | | 0.6t-0.02+0.1whent=0.4 | | 5t^2+135=10 | | 4X^2-16X+12=-8 | | 3t-8=4 | | -2(x-7)+x=14-x | | pm=3nm-4p | | 3x+1=6x-17 | | cos(3y)=x | | 12x^2-21x-108=0 | | -16=-4(x+3) | | (9x+2)-(3x-2)= | | 3x-7y=-29 | | 9+2n=31 | | 12=-3p | | 2p+2q=2 | | 11(2+x)-13=-11 | | (6x+9)+(-7x+9)= | | 8x+7(-13+x)=16 | | -3(4y-5)-y=-4(y-4) | | 0.5x+6-2x+0.5=7.2 |

Equations solver categories