x^2-2x-7=0

Simple and best practice solution for x^2-2x-7=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 x^2-2x-7=0 equation:


Simplifying
x2 + -2x + -7 = 0

Reorder the terms:
-7 + -2x + x2 = 0

Solving
-7 + -2x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '7' to each side of the equation.
-7 + -2x + 7 + x2 = 0 + 7

Reorder the terms:
-7 + 7 + -2x + x2 = 0 + 7

Combine like terms: -7 + 7 = 0
0 + -2x + x2 = 0 + 7
-2x + x2 = 0 + 7

Combine like terms: 0 + 7 = 7
-2x + x2 = 7

The x term is -2x.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2x + 1 + x2 = 7 + 1

Reorder the terms:
1 + -2x + x2 = 7 + 1

Combine like terms: 7 + 1 = 8
1 + -2x + x2 = 8

Factor a perfect square on the left side:
(x + -1)(x + -1) = 8

Calculate the square root of the right side: 2.828427125

Break this problem into two subproblems by setting 
(x + -1) equal to 2.828427125 and -2.828427125.

Subproblem 1

x + -1 = 2.828427125 Simplifying x + -1 = 2.828427125 Reorder the terms: -1 + x = 2.828427125 Solving -1 + x = 2.828427125 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + x = 2.828427125 + 1 Combine like terms: -1 + 1 = 0 0 + x = 2.828427125 + 1 x = 2.828427125 + 1 Combine like terms: 2.828427125 + 1 = 3.828427125 x = 3.828427125 Simplifying x = 3.828427125

Subproblem 2

x + -1 = -2.828427125 Simplifying x + -1 = -2.828427125 Reorder the terms: -1 + x = -2.828427125 Solving -1 + x = -2.828427125 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + x = -2.828427125 + 1 Combine like terms: -1 + 1 = 0 0 + x = -2.828427125 + 1 x = -2.828427125 + 1 Combine like terms: -2.828427125 + 1 = -1.828427125 x = -1.828427125 Simplifying x = -1.828427125

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.828427125, -1.828427125}

See similar equations:

| 109-7x=11x+23 | | 4x+2(x-5)=3x+2 | | 36x^2+24x+4=0 | | 13-7x=91-21x | | 2x^2-14=0 | | 3a=2(a+6) | | 9+2m-5=7m+5-4m | | -42-7x=9x+22 | | 5x+13=-43-9x | | 162-6x=6x+6 | | -10x-6=5-9x | | 56=-7a | | -64=8y | | -100=-10x | | -4=-4a | | -9b=9 | | -12=4n | | 2(x-3)+41=-3x | | 5(6z-1)-4(z+6)=19(z+1) | | 35=-7y | | 35=-7y | | 9n+6-4n=16 | | 43x=16x+1 | | -80=-y | | -a=24 | | -9b=-54 | | -9x=45 | | 0=2b | | 60x^5-240x^4+60x^3+600x^2-240x-480=0 | | 48=-8c | | 49=7a | | 12x^2-36x+27=0 |

Equations solver categories