7x^2-13x-40=0

Simple and best practice solution for 7x^2-13x-40=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 7x^2-13x-40=0 equation:


Simplifying
7x2 + -13x + -40 = 0

Reorder the terms:
-40 + -13x + 7x2 = 0

Solving
-40 + -13x + 7x2 = 0

Solving for variable 'x'.

Begin completing the square.  Divide all terms by
7 the coefficient of the squared term: 

Divide each side by '7'.
-5.714285714 + -1.857142857x + x2 = 0

Move the constant term to the right:

Add '5.714285714' to each side of the equation.
-5.714285714 + -1.857142857x + 5.714285714 + x2 = 0 + 5.714285714

Reorder the terms:
-5.714285714 + 5.714285714 + -1.857142857x + x2 = 0 + 5.714285714

Combine like terms: -5.714285714 + 5.714285714 = 0.000000000
0.000000000 + -1.857142857x + x2 = 0 + 5.714285714
-1.857142857x + x2 = 0 + 5.714285714

Combine like terms: 0 + 5.714285714 = 5.714285714
-1.857142857x + x2 = 5.714285714

The x term is -1.857142857x.  Take half its coefficient (-0.9285714285).
Square it (0.8622448978) and add it to both sides.

Add '0.8622448978' to each side of the equation.
-1.857142857x + 0.8622448978 + x2 = 5.714285714 + 0.8622448978

Reorder the terms:
0.8622448978 + -1.857142857x + x2 = 5.714285714 + 0.8622448978

Combine like terms: 5.714285714 + 0.8622448978 = 6.5765306118
0.8622448978 + -1.857142857x + x2 = 6.5765306118

Factor a perfect square on the left side:
(x + -0.9285714285)(x + -0.9285714285) = 6.5765306118

Calculate the square root of the right side: 2.564474724

Break this problem into two subproblems by setting 
(x + -0.9285714285) equal to 2.564474724 and -2.564474724.

Subproblem 1

x + -0.9285714285 = 2.564474724 Simplifying x + -0.9285714285 = 2.564474724 Reorder the terms: -0.9285714285 + x = 2.564474724 Solving -0.9285714285 + x = 2.564474724 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.9285714285' to each side of the equation. -0.9285714285 + 0.9285714285 + x = 2.564474724 + 0.9285714285 Combine like terms: -0.9285714285 + 0.9285714285 = 0.0000000000 0.0000000000 + x = 2.564474724 + 0.9285714285 x = 2.564474724 + 0.9285714285 Combine like terms: 2.564474724 + 0.9285714285 = 3.4930461525 x = 3.4930461525 Simplifying x = 3.4930461525

Subproblem 2

x + -0.9285714285 = -2.564474724 Simplifying x + -0.9285714285 = -2.564474724 Reorder the terms: -0.9285714285 + x = -2.564474724 Solving -0.9285714285 + x = -2.564474724 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '0.9285714285' to each side of the equation. -0.9285714285 + 0.9285714285 + x = -2.564474724 + 0.9285714285 Combine like terms: -0.9285714285 + 0.9285714285 = 0.0000000000 0.0000000000 + x = -2.564474724 + 0.9285714285 x = -2.564474724 + 0.9285714285 Combine like terms: -2.564474724 + 0.9285714285 = -1.6359032955 x = -1.6359032955 Simplifying x = -1.6359032955

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.4930461525, -1.6359032955}

See similar equations:

| 47x^2-25x=0 | | X+0.4*5=0.9(x+5) | | 10x+7+7x+3=0 | | 5x+15=3x+45 | | 4+1x=100 | | 7x+1.7-2.1x=0.4x-3.7 | | -0.7x+2.2=-2.3-1.3x | | X*10y=100 | | 72=(4)7(2)+2(2)H | | 72x^2-17x-72=0 | | -.8t+.4=.6 | | 2(x+4)+2=8x-6(x+9) | | x+4x+5x=30 | | 6x-8=30x+8 | | 6d+d=42 | | 4+2=c | | x+2x+7x+2=32 | | 49x^2-100y^6=0 | | -5(t-2)+9t=6t-4 | | 2x+6=2(x-5) | | v^2-v=36+4v | | 3x^2+4y^2=144 | | 17-2x=4x+9 | | .06(y-1)+.12y=.14y-.01(40) | | 0.5d=7 | | 56x+29x=42 | | b-4b= | | 5y-12=-67 | | 4y-16= | | (2x-7)(x-3)=10 | | 6.99+0.55=11.94x | | -3x=-2x+9 |

Equations solver categories