x^2+4x=31

Simple and best practice solution for x^2+4x=31 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+4x=31 equation:


Simplifying
x2 + 4x = 31

Reorder the terms:
4x + x2 = 31

Solving
4x + x2 = 31

Solving for variable 'x'.

Reorder the terms:
-31 + 4x + x2 = 31 + -31

Combine like terms: 31 + -31 = 0
-31 + 4x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '31' to each side of the equation.
-31 + 4x + 31 + x2 = 0 + 31

Reorder the terms:
-31 + 31 + 4x + x2 = 0 + 31

Combine like terms: -31 + 31 = 0
0 + 4x + x2 = 0 + 31
4x + x2 = 0 + 31

Combine like terms: 0 + 31 = 31
4x + x2 = 31

The x term is 4x.  Take half its coefficient (2).
Square it (4) and add it to both sides.

Add '4' to each side of the equation.
4x + 4 + x2 = 31 + 4

Reorder the terms:
4 + 4x + x2 = 31 + 4

Combine like terms: 31 + 4 = 35
4 + 4x + x2 = 35

Factor a perfect square on the left side:
(x + 2)(x + 2) = 35

Calculate the square root of the right side: 5.916079783

Break this problem into two subproblems by setting 
(x + 2) equal to 5.916079783 and -5.916079783.

Subproblem 1

x + 2 = 5.916079783 Simplifying x + 2 = 5.916079783 Reorder the terms: 2 + x = 5.916079783 Solving 2 + x = 5.916079783 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = 5.916079783 + -2 Combine like terms: 2 + -2 = 0 0 + x = 5.916079783 + -2 x = 5.916079783 + -2 Combine like terms: 5.916079783 + -2 = 3.916079783 x = 3.916079783 Simplifying x = 3.916079783

Subproblem 2

x + 2 = -5.916079783 Simplifying x + 2 = -5.916079783 Reorder the terms: 2 + x = -5.916079783 Solving 2 + x = -5.916079783 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2' to each side of the equation. 2 + -2 + x = -5.916079783 + -2 Combine like terms: 2 + -2 = 0 0 + x = -5.916079783 + -2 x = -5.916079783 + -2 Combine like terms: -5.916079783 + -2 = -7.916079783 x = -7.916079783 Simplifying x = -7.916079783

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.916079783, -7.916079783}

See similar equations:

| c^2-15c-34= | | 1/4(r-5/2)=1/8 | | 8x-21=2x+39 | | -3(3x+5)=3x-12 | | 19-(3m+7)=5+3m-11 | | 4t-7=t+8 | | y=-3x^2-12x+5 | | 1=1-7r-6r | | 5(x+9)+6x(5+x)=49 | | -x+(3x+3)=3 | | 0=-64x^3+128x^2-80x+15 | | 5/9(5)= | | -2(q-5)=10 | | 2u^2+7u+6=0 | | 4w-7=3b+1 | | 3.5+6.4x=x-3.4 | | 6y+y=-56 | | 2z+3=4z-2 | | 3(2h-4)=3 | | 0=-64x^4+128x^3-80x^2+15x | | A-7=2b-6 | | 1/3(n-5)=-2/3 | | Z-7=13 | | 12x-8=6x+16 | | 2x-1=105 | | p=2L+2B | | 2x^2-7xy+3y^2-8x+4y=x^2-2x-25y^2-20y-3 | | 7x+4y=-15 | | -3x+(5x+13)=3 | | 15x-7y=24 | | 4/3x-1/3=9 | | 4/3x-1/3-9 |

Equations solver categories