7x+x^2=40

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Solution for 7x+x^2=40 equation:


Simplifying
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 = 3.728416147 x = 3.728416147 Simplifying x = 3.728416147

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 = -10.728416147 x = -10.728416147 Simplifying x = -10.728416147

Solution

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

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