x*(x-7)=40

Simple and best practice solution for x*(x-7)=40 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)=40 equation:


Simplifying
x(x + -7) = 40

Reorder the terms:
x(-7 + x) = 40
(-7 * x + x * x) = 40
(-7x + x2) = 40

Solving
-7x + x2 = 40

Solving for variable 'x'.

Reorder the terms:
-40 + -7x + x2 = 40 + -40

Combine like terms: 40 + -40 = 0
-40 + -7x + x2 = 0

Begin completing the square.

Move the constant term to the right:

Add '40' to each side of the equation.
-40 + -7x + 40 + x2 = 0 + 40

Reorder the terms:
-40 + 40 + -7x + x2 = 0 + 40

Combine like terms: -40 + 40 = 0
0 + -7x + x2 = 0 + 40
-7x + x2 = 0 + 40

Combine like terms: 0 + 40 = 40
-7x + x2 = 40

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 = 40 + 12.25

Reorder the terms:
12.25 + -7x + x2 = 40 + 12.25

Combine like terms: 40 + 12.25 = 52.25
12.25 + -7x + x2 = 52.25

Factor a perfect square on the left side:
(x + -3.5)(x + -3.5) = 52.25

Calculate the square root of the right side: 7.228416147

Break this problem into two subproblems by setting 
(x + -3.5) equal to 7.228416147 and -7.228416147.

Subproblem 1

x + -3.5 = 7.228416147 Simplifying x + -3.5 = 7.228416147 Reorder the terms: -3.5 + x = 7.228416147 Solving -3.5 + x = 7.228416147 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 = 7.228416147 + 3.5 Combine like terms: -3.5 + 3.5 = 0.0 0.0 + x = 7.228416147 + 3.5 x = 7.228416147 + 3.5 Combine like terms: 7.228416147 + 3.5 = 10.728416147 x = 10.728416147 Simplifying x = 10.728416147

Subproblem 2

x + -3.5 = -7.228416147 Simplifying x + -3.5 = -7.228416147 Reorder the terms: -3.5 + x = -7.228416147 Solving -3.5 + x = -7.228416147 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 = -7.228416147 + 3.5 Combine like terms: -3.5 + 3.5 = 0.0 0.0 + x = -7.228416147 + 3.5 x = -7.228416147 + 3.5 Combine like terms: -7.228416147 + 3.5 = -3.728416147 x = -3.728416147 Simplifying x = -3.728416147

Solution

The solution to the problem is based on the solutions from the subproblems. x = {10.728416147, -3.728416147}

See similar equations:

| 2n-3(n+3)= | | 100+45000x=60000 | | 4(7x+-2)=48 | | -R-3(2+3r)=-36 | | lnt-ln(t-3)=1 | | 6n+1=4n+13 | | 100+200x=1200 | | N+4n=-20 | | 100+200=1200 | | -96=-6+5n | | x(2x+13)-33=0 | | 5x+27.45=31.20 | | (12x+5)+(6x-5)= | | 3.75x+12=35.00 | | 4.50x+10=329.50 | | 5y+5y=2+20 | | 200-20= | | -10(x-9)(x-1)-10(x-2)(x-1)=0 | | -4(y-7)+3(2y-1)= | | -23.5=-37.7 | | (10x+22)+(7x+34)= | | y+8.5=17.2whatisy | | 23x-3y=10 | | .04t=.76 | | -56=-7k^3 | | -3(3m-3)-3m=45 | | 3x-7=5x-9-x | | 2u=-30 | | 5x+51=7x | | 8p+13=2p-5 | | 5=a/4+9 | | A=9y+3yz |

Equations solver categories