4(x*x)+20x-15=0

Simple and best practice solution for 4(x*x)+20x-15=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 4(x*x)+20x-15=0 equation:


Simplifying
4(x * x) + 20x + -15 = 0

Multiply x * x
4(x2) + 20x + -15 = 0

Reorder the terms:
-15 + 20x + 4x2 = 0

Solving
-15 + 20x + 4x2 = 0

Solving for variable 'x'.

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

Divide each side by '4'.
-3.75 + 5x + x2 = 0

Move the constant term to the right:

Add '3.75' to each side of the equation.
-3.75 + 5x + 3.75 + x2 = 0 + 3.75

Reorder the terms:
-3.75 + 3.75 + 5x + x2 = 0 + 3.75

Combine like terms: -3.75 + 3.75 = 0.00
0.00 + 5x + x2 = 0 + 3.75
5x + x2 = 0 + 3.75

Combine like terms: 0 + 3.75 = 3.75
5x + x2 = 3.75

The x term is 5x.  Take half its coefficient (2.5).
Square it (6.25) and add it to both sides.

Add '6.25' to each side of the equation.
5x + 6.25 + x2 = 3.75 + 6.25

Reorder the terms:
6.25 + 5x + x2 = 3.75 + 6.25

Combine like terms: 3.75 + 6.25 = 10
6.25 + 5x + x2 = 10

Factor a perfect square on the left side:
(x + 2.5)(x + 2.5) = 10

Calculate the square root of the right side: 3.16227766

Break this problem into two subproblems by setting 
(x + 2.5) equal to 3.16227766 and -3.16227766.

Subproblem 1

x + 2.5 = 3.16227766 Simplifying x + 2.5 = 3.16227766 Reorder the terms: 2.5 + x = 3.16227766 Solving 2.5 + x = 3.16227766 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2.5' to each side of the equation. 2.5 + -2.5 + x = 3.16227766 + -2.5 Combine like terms: 2.5 + -2.5 = 0.0 0.0 + x = 3.16227766 + -2.5 x = 3.16227766 + -2.5 Combine like terms: 3.16227766 + -2.5 = 0.66227766 x = 0.66227766 Simplifying x = 0.66227766

Subproblem 2

x + 2.5 = -3.16227766 Simplifying x + 2.5 = -3.16227766 Reorder the terms: 2.5 + x = -3.16227766 Solving 2.5 + x = -3.16227766 Solving for variable 'x'. Move all terms containing x to the left, all other terms to the right. Add '-2.5' to each side of the equation. 2.5 + -2.5 + x = -3.16227766 + -2.5 Combine like terms: 2.5 + -2.5 = 0.0 0.0 + x = -3.16227766 + -2.5 x = -3.16227766 + -2.5 Combine like terms: -3.16227766 + -2.5 = -5.66227766 x = -5.66227766 Simplifying x = -5.66227766

Solution

The solution to the problem is based on the solutions from the subproblems. x = {0.66227766, -5.66227766}

See similar equations:

| x=cos(90) | | x=50/100 | | F(x)=8-9x | | 2(2x)+2(2x+1)=24 | | 2x-4=6-12 | | x+(x-2)+(x-3)=16 | | 6x+x-280=180 | | 3cos(2x)=sin(x)+2 | | a+b+x=8a+b | | 4x+6=21-3x+6 | | 4..2/3..5=58/15 | | 58/15=4..2/3..5 | | 58/16=4..2/3..5 | | 8x+3=8r | | 58/16=2/3 | | 10(s-9)=-161 | | ln(x+2)-3x=0 | | 16-3x=-x | | 12/23=x/-138 | | -0.7=-q+-7 | | 5S=13 | | 6/19=x/76 | | 6.3/x=7 | | 13x-42=3-2x | | 1x^2=4 | | 10lnx=0 | | 5-3y=7.58 | | 7-8/x=-1 | | 1/x=-0.2 | | 5pq+pq= | | -(4x-6)+3(2x-4)+3=1 | | (2x-y-2)dx+(x+y-4)dy=0 |

Equations solver categories