7x+x^2=15

Simple and best practice solution for 7x+x^2=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 7x+x^2=15 equation:


Simplifying
7x + x2 = 15

Solving
7x + x2 = 15

Solving for variable 'x'.

Reorder the terms:
-15 + 7x + x2 = 15 + -15

Combine like terms: 15 + -15 = 0
-15 + 7x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '15' to each side of the equation.
-15 + 7x + 15 + x2 = 0 + 15

Reorder the terms:
-15 + 15 + 7x + x2 = 0 + 15

Combine like terms: -15 + 15 = 0
0 + 7x + x2 = 0 + 15
7x + x2 = 0 + 15

Combine like terms: 0 + 15 = 15
7x + x2 = 15

The x term is 7x.  Take half its coefficient (3.5).
Square it (12.25) and add it to both sides.

Add '12.25' to each side of the equation.
7x + 12.25 + x2 = 15 + 12.25

Reorder the terms:
12.25 + 7x + x2 = 15 + 12.25

Combine like terms: 15 + 12.25 = 27.25
12.25 + 7x + x2 = 27.25

Factor a perfect square on the left side:
(x + 3.5)(x + 3.5) = 27.25

Calculate the square root of the right side: 5.220153254

Break this problem into two subproblems by setting 
(x + 3.5) equal to 5.220153254 and -5.220153254.

Subproblem 1

x + 3.5 = 5.220153254 Simplifying x + 3.5 = 5.220153254 Reorder the terms: 3.5 + x = 5.220153254 Solving 3.5 + x = 5.220153254 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-3.5' to each side of the equation. 3.5 + -3.5 + x = 5.220153254 + -3.5 Combine like terms: 3.5 + -3.5 = 0.0 0.0 + x = 5.220153254 + -3.5 x = 5.220153254 + -3.5 Combine like terms: 5.220153254 + -3.5 = 1.720153254 x = 1.720153254 Simplifying x = 1.720153254

Subproblem 2

x + 3.5 = -5.220153254 Simplifying x + 3.5 = -5.220153254 Reorder the terms: 3.5 + x = -5.220153254 Solving 3.5 + x = -5.220153254 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-3.5' to each side of the equation. 3.5 + -3.5 + x = -5.220153254 + -3.5 Combine like terms: 3.5 + -3.5 = 0.0 0.0 + x = -5.220153254 + -3.5 x = -5.220153254 + -3.5 Combine like terms: -5.220153254 + -3.5 = -8.720153254 x = -8.720153254 Simplifying x = -8.720153254

Solution

The solution to the problem is based on the solutions from the subproblems. x = {1.720153254, -8.720153254}

See similar equations:

| Ln(2x-3)=1.5 | | 5a^2-22a-15=0 | | z^2+iz-2z+2=0 | | 7X+6-7*2=6 | | 20x+x^2=122 | | 5x-2x+8=36 | | 17X*8/6=75 | | 7n+34=-5(4-5n) | | t/58=12 | | 12=194-y | | 7/9=b-10 | | -4(1+3a)-3=-39-89 | | x+x+17x+2x=2200 | | 30y+6=18fraction | | 12.4*0.42= | | 5+3(-1)=2 | | x+2x+4+0.5*x=82 | | -40-7m=7+4(-2-8m) | | x+2x+4+0.5*x=77 | | 8x^2+7x-13=3x^2+12x-8 | | 8+2w=4 | | 3.5*x=22 | | 1.6=.8x+4 | | f(x)=2+5lnx | | x+2x+4+0.5*x=26 | | x+2x+4+0.5*x=22 | | 16x*x+8x-36=0 | | 5x+3x+8=26+6x | | 6m-8=4m-4 | | 16x*2+8x-36=0 | | lnxsquared=9 | | -27x^3+18x-4=0 |

Equations solver categories