5x^2-21x+12=

Simple and best practice solution for 5x^2-21x+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 5x^2-21x+12= equation:


Simplifying
5x2 + -21x + 12 = 0

Reorder the terms:
12 + -21x + 5x2 = 0

Solving
12 + -21x + 5x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
5 the coefficient of the squared term: 

Divide each side by '5'.
2.4 + -4.2x + x2 = 0

Move the constant term to the right:

Add '-2.4' to each side of the equation.
2.4 + -4.2x + -2.4 + x2 = 0 + -2.4

Reorder the terms:
2.4 + -2.4 + -4.2x + x2 = 0 + -2.4

Combine like terms: 2.4 + -2.4 = 0.0
0.0 + -4.2x + x2 = 0 + -2.4
-4.2x + x2 = 0 + -2.4

Combine like terms: 0 + -2.4 = -2.4
-4.2x + x2 = -2.4

The x term is -4.2x.  Take half its coefficient (-2.1).
Square it (4.41) and add it to both sides.

Add '4.41' to each side of the equation.
-4.2x + 4.41 + x2 = -2.4 + 4.41

Reorder the terms:
4.41 + -4.2x + x2 = -2.4 + 4.41

Combine like terms: -2.4 + 4.41 = 2.01
4.41 + -4.2x + x2 = 2.01

Factor a perfect square on the left side:
(x + -2.1)(x + -2.1) = 2.01

Calculate the square root of the right side: 1.417744688

Break this problem into two subproblems by setting 
(x + -2.1) equal to 1.417744688 and -1.417744688.

Subproblem 1

x + -2.1 = 1.417744688 Simplifying x + -2.1 = 1.417744688 Reorder the terms: -2.1 + x = 1.417744688 Solving -2.1 + x = 1.417744688 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2.1' to each side of the equation. -2.1 + 2.1 + x = 1.417744688 + 2.1 Combine like terms: -2.1 + 2.1 = 0.0 0.0 + x = 1.417744688 + 2.1 x = 1.417744688 + 2.1 Combine like terms: 1.417744688 + 2.1 = 3.517744688 x = 3.517744688 Simplifying x = 3.517744688

Subproblem 2

x + -2.1 = -1.417744688 Simplifying x + -2.1 = -1.417744688 Reorder the terms: -2.1 + x = -1.417744688 Solving -2.1 + x = -1.417744688 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '2.1' to each side of the equation. -2.1 + 2.1 + x = -1.417744688 + 2.1 Combine like terms: -2.1 + 2.1 = 0.0 0.0 + x = -1.417744688 + 2.1 x = -1.417744688 + 2.1 Combine like terms: -1.417744688 + 2.1 = 0.682255312 x = 0.682255312 Simplifying x = 0.682255312

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.517744688, 0.682255312}

See similar equations:

| 2(y+7)-6y=30 | | 5d-7=-252 | | 1/2w-3/7=-4/5 | | 7x-5=121 | | -7/4-2/3w=-9/5 | | -5x^3(3x^3+2)= | | 3(g+5)=45 | | 3x/25 | | 25x^2+200x-400=0 | | -4(w-1)=6w-26 | | -3y^5(2y^3+3)= | | -2/5=-1/2w-5/3 | | 0.2a^2+12a+0.9=0 | | 5(x-6)=4x | | 3=w/5-7 | | -2c^6(5c^3+6)= | | 3(3x-9)=-18 | | -4b^4(5b^2+6)= | | -3(x-7)=2x-4 | | 2(v-6)=-28 | | K+4k*k=2 | | 4x^3(6x^2)= | | 7(y-2)=3y-46 | | 3a^3(-3a^4)= | | 4(5)+7(4)=0 | | 6b^3(-2b^3)= | | z-z+z+3z=20 | | 5x-2y=3x-y | | .5r-3=12-1.5r | | 8x^3(3x^2)= | | x-.59x= | | 96+4x=360 |

Equations solver categories