7x^2-20x-18=0

Simple and best practice solution for 7x^2-20x-18=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^2-20x-18=0 equation:


Simplifying
7x2 + -20x + -18 = 0

Reorder the terms:
-18 + -20x + 7x2 = 0

Solving
-18 + -20x + 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'.
-2.571428571 + -2.857142857x + x2 = 0

Move the constant term to the right:

Add '2.571428571' to each side of the equation.
-2.571428571 + -2.857142857x + 2.571428571 + x2 = 0 + 2.571428571

Reorder the terms:
-2.571428571 + 2.571428571 + -2.857142857x + x2 = 0 + 2.571428571

Combine like terms: -2.571428571 + 2.571428571 = 0.000000000
0.000000000 + -2.857142857x + x2 = 0 + 2.571428571
-2.857142857x + x2 = 0 + 2.571428571

Combine like terms: 0 + 2.571428571 = 2.571428571
-2.857142857x + x2 = 2.571428571

The x term is -2.857142857x.  Take half its coefficient (-1.428571429).
Square it (2.040816328) and add it to both sides.

Add '2.040816328' to each side of the equation.
-2.857142857x + 2.040816328 + x2 = 2.571428571 + 2.040816328

Reorder the terms:
2.040816328 + -2.857142857x + x2 = 2.571428571 + 2.040816328

Combine like terms: 2.571428571 + 2.040816328 = 4.612244899
2.040816328 + -2.857142857x + x2 = 4.612244899

Factor a perfect square on the left side:
(x + -1.428571429)(x + -1.428571429) = 4.612244899

Calculate the square root of the right side: 2.147613769

Break this problem into two subproblems by setting 
(x + -1.428571429) equal to 2.147613769 and -2.147613769.

Subproblem 1

x + -1.428571429 = 2.147613769 Simplifying x + -1.428571429 = 2.147613769 Reorder the terms: -1.428571429 + x = 2.147613769 Solving -1.428571429 + x = 2.147613769 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.428571429' to each side of the equation. -1.428571429 + 1.428571429 + x = 2.147613769 + 1.428571429 Combine like terms: -1.428571429 + 1.428571429 = 0.000000000 0.000000000 + x = 2.147613769 + 1.428571429 x = 2.147613769 + 1.428571429 Combine like terms: 2.147613769 + 1.428571429 = 3.576185198 x = 3.576185198 Simplifying x = 3.576185198

Subproblem 2

x + -1.428571429 = -2.147613769 Simplifying x + -1.428571429 = -2.147613769 Reorder the terms: -1.428571429 + x = -2.147613769 Solving -1.428571429 + x = -2.147613769 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '1.428571429' to each side of the equation. -1.428571429 + 1.428571429 + x = -2.147613769 + 1.428571429 Combine like terms: -1.428571429 + 1.428571429 = 0.000000000 0.000000000 + x = -2.147613769 + 1.428571429 x = -2.147613769 + 1.428571429 Combine like terms: -2.147613769 + 1.428571429 = -0.71904234 x = -0.71904234 Simplifying x = -0.71904234

Solution

The solution to the problem is based on the solutions from the subproblems. x = {3.576185198, -0.71904234}

See similar equations:

| 3g+8=7 | | 7r+9r= | | 11x+2-18+2=360 | | 34(x-1)+x=4(x+2) | | 11x^2+8x+7=0 | | 2+7x=4x+x | | -68+8x=136-4x | | 11x-12=6x+13 | | 4+15y-3=9y+56-5y | | 0.12r-0.3=0.06 | | a-2/a2-16x-4a-16/-4a+8 | | 3x^2/3-8x^1/3-3=0 | | 7+3=(3a-3)10 | | 9(2x-7)=9x | | 73=(3a-3)10 | | (y-5)(-7y^2+6y+1)= | | 7x+8-2(2x-3)= | | 8(2+n)-3=72 | | (9a^3/5t^5)*(25t^8/81a) | | 5+43=8x+13 | | x^2+25x-n=0 | | 0=5x^2-3x | | 2y-5=4x+1 | | x/3=309 | | 0=-9x^2+4x | | 7x-16x= | | 0=-28x^2+7x | | 1/4(x-2)=1/3(2x+6) | | 8(6y^2-2y+7)-3(6y^2-4y+4)= | | x^2+26x+23=0 | | 7x-4x-2=2x-5 | | 5(x-3)-15-0= |

Equations solver categories