3x^2+x=15

Simple and best practice solution for 3x^2+x=15 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=15 equation:


Simplifying
3x2 + x = 15

Reorder the terms:
x + 3x2 = 15

Solving
x + 3x2 = 15

Solving for variable 'x'.

Reorder the terms:
-15 + x + 3x2 = 15 + -15

Combine like terms: 15 + -15 = 0
-15 + x + 3x2 = 0

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

Divide each side by '3'.
-5 + 0.3333333333x + x2 = 0

Move the constant term to the right:

Add '5' to each side of the equation.
-5 + 0.3333333333x + 5 + x2 = 0 + 5

Reorder the terms:
-5 + 5 + 0.3333333333x + x2 = 0 + 5

Combine like terms: -5 + 5 = 0
0 + 0.3333333333x + x2 = 0 + 5
0.3333333333x + x2 = 0 + 5

Combine like terms: 0 + 5 = 5
0.3333333333x + x2 = 5

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 = 5 + 0.25

Reorder the terms:
0.25 + 0.3333333333x + x2 = 5 + 0.25

Combine like terms: 5 + 0.25 = 5.25
0.25 + 0.3333333333x + x2 = 5.25

Factor a perfect square on the left side:
(x + 0.5)(x + 0.5) = 5.25

Calculate the square root of the right side: 2.291287847

Break this problem into two subproblems by setting 
(x + 0.5) equal to 2.291287847 and -2.291287847.

Subproblem 1

x + 0.5 = 2.291287847 Simplifying x + 0.5 = 2.291287847 Reorder the terms: 0.5 + x = 2.291287847 Solving 0.5 + x = 2.291287847 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 = 2.291287847 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = 2.291287847 + -0.5 x = 2.291287847 + -0.5 Combine like terms: 2.291287847 + -0.5 = 1.791287847 x = 1.791287847 Simplifying x = 1.791287847

Subproblem 2

x + 0.5 = -2.291287847 Simplifying x + 0.5 = -2.291287847 Reorder the terms: 0.5 + x = -2.291287847 Solving 0.5 + x = -2.291287847 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 = -2.291287847 + -0.5 Combine like terms: 0.5 + -0.5 = 0.0 0.0 + x = -2.291287847 + -0.5 x = -2.291287847 + -0.5 Combine like terms: -2.291287847 + -0.5 = -2.791287847 x = -2.791287847 Simplifying x = -2.791287847

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.791287847, -2.791287847}

See similar equations:

| 6x+7-2x-2= | | 36-5x=1 | | 7z+9z^2= | | 4yx^2-2yx^2=0 | | 2x+897345+2987529x+64864+5614846x=1 | | y+.27=x+0.05 | | 11c=33 | | 5a+4b-6c=-24 | | 5a+4b-6c=24 | | y+.05=x+.27 | | x+.05=y+.27 | | 5.2+2=3 | | g(10)+1=3x+1 | | b*5=25 | | x+-37=-19 | | -9z+10=-8z-4 | | 3a^2+4=12a | | 2m-4.5=9 | | 8x-10=3(2x-6) | | 19+9j=100 | | x=9+5 | | 5=1/4x-2 | | 1/4a+3=2 | | H-5.3=26 | | 18d-21-15d=3 | | 5n^2-5=-4n | | -16+8a=-5(9a+4) | | (8+7i)-(-4+10i)= | | 10x+13=153 | | -4x+10y=20 | | 5y+22=82 | | x^2+ix=0 |

Equations solver categories