x(x-7)=91

Simple and best practice solution for x(x-7)=91 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(x-7)=91 equation:


Simplifying
x(x + -7) = 91

Reorder the terms:
x(-7 + x) = 91
(-7 * x + x * x) = 91
(-7x + x2) = 91

Solving
-7x + x2 = 91

Solving for variable 'x'.

Reorder the terms:
-91 + -7x + x2 = 91 + -91

Combine like terms: 91 + -91 = 0
-91 + -7x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '91' to each side of the equation.
-91 + -7x + 91 + x2 = 0 + 91

Reorder the terms:
-91 + 91 + -7x + x2 = 0 + 91

Combine like terms: -91 + 91 = 0
0 + -7x + x2 = 0 + 91
-7x + x2 = 0 + 91

Combine like terms: 0 + 91 = 91
-7x + x2 = 91

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 = 91 + 12.25

Reorder the terms:
12.25 + -7x + x2 = 91 + 12.25

Combine like terms: 91 + 12.25 = 103.25
12.25 + -7x + x2 = 103.25

Factor a perfect square on the left side:
(x + -3.5)(x + -3.5) = 103.25

Calculate the square root of the right side: 10.161200716

Break this problem into two subproblems by setting 
(x + -3.5) equal to 10.161200716 and -10.161200716.

Subproblem 1

x + -3.5 = 10.161200716 Simplifying x + -3.5 = 10.161200716 Reorder the terms: -3.5 + x = 10.161200716 Solving -3.5 + x = 10.161200716 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 = 10.161200716 + 3.5 Combine like terms: -3.5 + 3.5 = 0.0 0.0 + x = 10.161200716 + 3.5 x = 10.161200716 + 3.5 Combine like terms: 10.161200716 + 3.5 = 13.661200716 x = 13.661200716 Simplifying x = 13.661200716

Subproblem 2

x + -3.5 = -10.161200716 Simplifying x + -3.5 = -10.161200716 Reorder the terms: -3.5 + x = -10.161200716 Solving -3.5 + x = -10.161200716 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 = -10.161200716 + 3.5 Combine like terms: -3.5 + 3.5 = 0.0 0.0 + x = -10.161200716 + 3.5 x = -10.161200716 + 3.5 Combine like terms: -10.161200716 + 3.5 = -6.661200716 x = -6.661200716 Simplifying x = -6.661200716

Solution

The solution to the problem is based on the solutions from the subproblems. x = {13.661200716, -6.661200716}

See similar equations:

| 2(y-3)=4y | | -7x+18=-8x-1 | | 21/25=y/100 | | 3-(x-3)=4x-4 | | 2.5^1/t=1.04 | | 13=12+(-5)-3t | | 3(1+4n)+2(5n-3)=25 | | -4x+9=-3x+1 | | -5x-2=26-2x | | 9x-19=8x+10 | | 6+3x+48=90 | | 10+y-6=2y+25 | | 2x+40+3x-25=180 | | X^2+6x-37=3 | | 5w+8y+8x+7x-14y+4w= | | x^2=y^2+2y+13 | | 32+112+4y+8=180 | | 44=4u+16 | | 9x+14=4x+9 | | 3a+-5a=-14 | | x^2-0.3x-0.6=0 | | C=2*19*3.14 | | 72+52+4x-12=180 | | 180/365 | | -5x+4(2+2x)=-1 | | 17x+30=190-15x | | 5v-11=34 | | x^2-0.3x+0.6=0 | | 2*0.5x^2=16 | | 12=b-6.3 | | 3t+15=3t-4 | | 3x+2+5x-3=10x-19 |

Equations solver categories