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 = 5.274917218 x = 5.274917218 Simplifying x = 5.274917218

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 = -2.274917218 x = -2.274917218 Simplifying x = -2.274917218

Solution

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

See similar equations:

| X+15=120 | | y^2+6y-9=0 | | 5+11=45+x | | -8v+18=9v-11v | | X^3-2x^2-5x=0 | | z+19=22 | | 4x+4/7+3x-1/7=2/7 | | w^2+4w-2=0 | | t^2=3t+40 | | 5y+25=30 | | x^2+x-3x-3=22-2x | | 142.39=2.55h+73.54 | | 6x-20=46 | | 5x=3x-6 | | -5x+23+7x+23=-4 | | 3x^3+21x^2-54x=0 | | 24x+60x= | | 3x+x=-28 | | 2z^2=7z-6 | | 0=x^3-5x^2-12x+60 | | (x+1)(x+2)=42 | | 3x-5y=12 | | 9x^3+4x-100=0 | | a-7/10=a-2/8 | | 2k-8=4(k+1) | | 3(4x+6)=-9x+12 | | 8-4x*14+10=5x+10 | | x+15+x=55 | | x+8+5x=31-2x | | 25v^2-9w^2= | | 3(x+6)=-5(x+6)+15 | | x^2-x=870 |

Equations solver categories