x^2+3x=12

Simple and best practice solution for x^2+3x=12 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+3x=12 equation:


Simplifying
x2 + 3x = 12

Reorder the terms:
3x + x2 = 12

Solving
3x + x2 = 12

Solving for variable 'x'.

Reorder the terms:
-12 + 3x + x2 = 12 + -12

Combine like terms: 12 + -12 = 0
-12 + 3x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '12' to each side of the equation.
-12 + 3x + 12 + x2 = 0 + 12

Reorder the terms:
-12 + 12 + 3x + x2 = 0 + 12

Combine like terms: -12 + 12 = 0
0 + 3x + x2 = 0 + 12
3x + x2 = 0 + 12

Combine like terms: 0 + 12 = 12
3x + x2 = 12

The x term is 3x.  Take half its coefficient (1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
3x + 2.25 + x2 = 12 + 2.25

Reorder the terms:
2.25 + 3x + x2 = 12 + 2.25

Combine like terms: 12 + 2.25 = 14.25
2.25 + 3x + x2 = 14.25

Factor a perfect square on the left side:
(x + 1.5)(x + 1.5) = 14.25

Calculate the square root of the right side: 3.774917218

Break this problem into two subproblems by setting 
(x + 1.5) equal to 3.774917218 and -3.774917218.

Subproblem 1

x + 1.5 = 3.774917218 Simplifying x + 1.5 = 3.774917218 Reorder the terms: 1.5 + x = 3.774917218 Solving 1.5 + x = 3.774917218 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.5' to each side of the equation. 1.5 + -1.5 + x = 3.774917218 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = 3.774917218 + -1.5 x = 3.774917218 + -1.5 Combine like terms: 3.774917218 + -1.5 = 2.274917218 x = 2.274917218 Simplifying x = 2.274917218

Subproblem 2

x + 1.5 = -3.774917218 Simplifying x + 1.5 = -3.774917218 Reorder the terms: 1.5 + x = -3.774917218 Solving 1.5 + x = -3.774917218 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-1.5' to each side of the equation. 1.5 + -1.5 + x = -3.774917218 + -1.5 Combine like terms: 1.5 + -1.5 = 0.0 0.0 + x = -3.774917218 + -1.5 x = -3.774917218 + -1.5 Combine like terms: -3.774917218 + -1.5 = -5.274917218 x = -5.274917218 Simplifying x = -5.274917218

Solution

The solution to the problem is based on the solutions from the subproblems. x = {2.274917218, -5.274917218}

See similar equations:

| -14=3a-2 | | 3x^2-54=0 | | 6x^2-12=x | | 7(2x+15)-28=35(1-x)-7 | | 3x+17=-11+x | | -2x-7=2x-10 | | -x+100=-1.5x+125 | | x^2+3=2x+5 | | 4x^2=5 | | y=2x^2-3x | | -x+15=6-4x | | -x+15=-6-4x | | y=2x*2-3x | | 6m-15=5+4m | | 50x^3+3500x-5000=0 | | x^3-8x^2-x+6=0 | | -x-19=0 | | 2x+10=x+16 | | 3+5=4 | | -x-8=-9 | | 0=x^2+10x+1 | | -x+17=-10 | | -x-17=-10 | | x(x-1)=6 | | x^4+x^3+x^3+x=0 | | (-3x+8)-(2y-3)i=-11-4i | | -x+15=6 | | 10=(5x-10)+2yi | | 2y-6=0 | | 10+8x=80+x | | b(b+16)=0 | | (X+5)-8yi=-3i |

Equations solver categories