3x^2+x-42=0

Simple and best practice solution for 3x^2+x-42=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 3x^2+x-42=0 equation:


Simplifying
3x2 + x + -42 = 0

Reorder the terms:
-42 + x + 3x2 = 0

Solving
-42 + x + 3x2 = 0

Solving for variable 'x'.

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

Divide each side by '3'.
-14 + 0.3333333333x + x2 = 0

Move the constant term to the right:

Add '14' to each side of the equation.
-14 + 0.3333333333x + 14 + x2 = 0 + 14

Reorder the terms:
-14 + 14 + 0.3333333333x + x2 = 0 + 14

Combine like terms: -14 + 14 = 0
0 + 0.3333333333x + x2 = 0 + 14
0.3333333333x + x2 = 0 + 14

Combine like terms: 0 + 14 = 14
0.3333333333x + x2 = 14

The x term is x.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
0.3333333333x + 0.25 + x2 = 14 + 0.25

Reorder the terms:
0.25 + 0.3333333333x + x2 = 14 + 0.25

Combine like terms: 14 + 0.25 = 14.25
0.25 + 0.3333333333x + x2 = 14.25

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = 14.25

Calculate the square root of the right side: 3.774917218

Break this problem into two subproblems by setting 
(x + 0.5) equal to 3.774917218 and -3.774917218.

Subproblem 1

x + 0.5 = 3.774917218 Simplifying x + 0.5 = 3.774917218 Reorder the terms: 0.5 + x = 3.774917218 Solving 0.5 + x = 3.774917218 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = 3.774917218 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = 3.774917218 + -0.5 x = 3.774917218 + -0.5 Combine like terms: 3.774917218 + -0.5 = 3.274917218 x = 3.274917218 Simplifying x = 3.274917218

Subproblem 2

x + 0.5 = -3.774917218 Simplifying x + 0.5 = -3.774917218 Reorder the terms: 0.5 + x = -3.774917218 Solving 0.5 + x = -3.774917218 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-0.5' to each side of the equation. 0.5 + -0.5 + x = -3.774917218 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = -3.774917218 + -0.5 x = -3.774917218 + -0.5 Combine like terms: -3.774917218 + -0.5 = -4.274917218 x = -4.274917218 Simplifying x = -4.274917218

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.274917218, -4.274917218}

See similar equations:

| 0.7y-0.3y=6.4 | | 2x^3-15x^2-84x+5=0 | | A+b=w-2 | | 3y=88-2x | | 4+3x-1=9x+11-5x | | 0.16(24)+0.04x=0.08(18+x) | | -(6x+3)-(8x-7)=8-(5x+1) | | 6m-8=2+9m-6 | | 10-4x=-2+8x | | 2x+13=37 | | 3t=1 | | 4y-12=-3y | | [x]-y=2 | | 3t=-1 | | 4x+43x+30x=0 | | 2y=1-xy | | 1-0x=0 | | .14y+6=-19 | | 3x-2x=6 | | 15+k=-9 | | b+2b+(b+15)=95 | | 6=13+q | | 11z=-33 | | 6(-4)= | | 8*-7= | | (x^2)=-4 | | y+23=-1 | | -29+q=4 | | (2x+6)*(x+5)=a | | d-4=-25 | | 5(2x-3)+7=10x-8 | | (x+100)+(x)+(x-50)=500 |

Equations solver categories