x^2-3x-20=0

Simple and best practice solution for x^2-3x-20=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 x^2-3x-20=0 equation: 


Simplifying
x2 + -3x + -20 = 0

Reorder the terms:
-20 + -3x + x2 = 0

Solving
-20 + -3x + x2 = 0

Solving for variable 'x'.

Begin completing the square.

Move the constant term to the right:

Add '20' to each side of the equation.
-20 + -3x + 20 + x2 = 0 + 20

Reorder the terms:
-20 + 20 + -3x + x2 = 0 + 20

Combine like terms: -20 + 20 = 0
0 + -3x + x2 = 0 + 20
-3x + x2 = 0 + 20

Combine like terms: 0 + 20 = 20
-3x + x2 = 20

The x term is -3x.  Take half its coefficient (-1.5).
Square it (2.25) and add it to both sides.

Add '2.25' to each side of the equation.
-3x + 2.25 + x2 = 20 + 2.25

Reorder the terms:
2.25 + -3x + x2 = 20 + 2.25

Combine like terms: 20 + 2.25 = 22.25
2.25 + -3x + x2 = 22.25

Factor a perfect square on the left side:
(x + -1.5)(x + -1.5) = 22.25

Calculate the square root of the right side: 4.716990566

Break this problem into two subproblems by setting 
(x + -1.5) equal to 4.716990566 and -4.716990566.


Subproblem 1
x + -1.5 = 4.716990566

Simplifying
x + -1.5 = 4.716990566

Reorder the terms:
-1.5 + x = 4.716990566

Solving
-1.5 + x = 4.716990566

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '1.5' to each side of the equation.
-1.5 + 1.5 + x = 4.716990566 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + x = 4.716990566 + 1.5
x = 4.716990566 + 1.5

Combine like terms: 4.716990566 + 1.5 = 6.216990566
x = 6.216990566

Simplifying
x = 6.216990566


Subproblem 2
x + -1.5 = -4.716990566

Simplifying
x + -1.5 = -4.716990566

Reorder the terms:
-1.5 + x = -4.716990566

Solving
-1.5 + x = -4.716990566

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '1.5' to each side of the equation.
-1.5 + 1.5 + x = -4.716990566 + 1.5

Combine like terms: -1.5 + 1.5 = 0.0
0.0 + x = -4.716990566 + 1.5
x = -4.716990566 + 1.5

Combine like terms: -4.716990566 + 1.5 = -3.216990566
x = -3.216990566

Simplifying
x = -3.216990566


Solution
The solution to the problem is based on the solutions
from the subproblems.
x = {6.216990566, -3.216990566}

See similar equations:

| 3x+7=0 | | 22=5(2y+3)-3y | | -z=9 | | (3x-2)-8=-6 | | 12=0.5p+2.5 | | 15(j-3)+3j=45 | | 4(y+1)=8 | | -400=-10(-5B) | | -5x+14=7x-28 | | 4x^2+12x=-9 | | x*x-81=0 | | 3(4c-5)-2c=0 | | 3c-7(-c+4)=2-(c-4)+6c | | 11m-19m=40 | | 16x-8=21-x | | 8m=64 | | 8-8=15m-6m | | 5-2(3-2y)=4(6y-4)+8 | | 5-2(3-2)=4(6-4)+8 | | 12x-15x=6 | | -9x=225 | | 7r-1=5r-13 | | -9x= | | 14(x-6)=28 | | 13x^3+26x^2-13x=0 | | b-1+5b=28 | | k^2-5k+6= | | 0.3=8 | | 10x+24y=75 | | 8w=59 | | 3x+4z=7-xy | | 5v-3=4-2v |

Equations solver categories