r^2=2r+4

Simple and best practice solution for r^2=2r+4 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 r^2=2r+4 equation:


Simplifying
r2 = 2r + 4

Reorder the terms:
r2 = 4 + 2r

Solving
r2 = 4 + 2r

Solving for variable 'r'.

Reorder the terms:
-4 + -2r + r2 = 4 + 2r + -4 + -2r

Reorder the terms:
-4 + -2r + r2 = 4 + -4 + 2r + -2r

Combine like terms: 4 + -4 = 0
-4 + -2r + r2 = 0 + 2r + -2r
-4 + -2r + r2 = 2r + -2r

Combine like terms: 2r + -2r = 0
-4 + -2r + r2 = 0

Begin completing the square.

Move the constant term to the right:

Add '4' to each side of the equation.
-4 + -2r + 4 + r2 = 0 + 4

Reorder the terms:
-4 + 4 + -2r + r2 = 0 + 4

Combine like terms: -4 + 4 = 0
0 + -2r + r2 = 0 + 4
-2r + r2 = 0 + 4

Combine like terms: 0 + 4 = 4
-2r + r2 = 4

The r term is -2r.  Take half its coefficient (-1).
Square it (1) and add it to both sides.

Add '1' to each side of the equation.
-2r + 1 + r2 = 4 + 1

Reorder the terms:
1 + -2r + r2 = 4 + 1

Combine like terms: 4 + 1 = 5
1 + -2r + r2 = 5

Factor a perfect square on the left side:
(r + -1)(r + -1) = 5

Calculate the square root of the right side: 2.236067978

Break this problem into two subproblems by setting 
(r + -1) equal to 2.236067978 and -2.236067978.

Subproblem 1

r + -1 = 2.236067978 Simplifying r + -1 = 2.236067978 Reorder the terms: -1 + r = 2.236067978 Solving -1 + r = 2.236067978 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + r = 2.236067978 + 1 Combine like terms: -1 + 1 = 0 0 + r = 2.236067978 + 1 r = 2.236067978 + 1 Combine like terms: 2.236067978 + 1 = 3.236067978 r = 3.236067978 Simplifying r = 3.236067978

Subproblem 2

r + -1 = -2.236067978 Simplifying r + -1 = -2.236067978 Reorder the terms: -1 + r = -2.236067978 Solving -1 + r = -2.236067978 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '1' to each side of the equation. -1 + 1 + r = -2.236067978 + 1 Combine like terms: -1 + 1 = 0 0 + r = -2.236067978 + 1 r = -2.236067978 + 1 Combine like terms: -2.236067978 + 1 = -1.236067978 r = -1.236067978 Simplifying r = -1.236067978

Solution

The solution to the problem is based on the solutions from the subproblems. r = {3.236067978, -1.236067978}

See similar equations:

| 4*2-25=0 | | x+x*.5=1.8 | | -7x+4+6x=-7 | | 3x^2-2x=12x+5 | | Y/4-12=27 | | 2x+7-5x=4 | | 18=4j+6 | | 3x+9-19=8x-2+6 | | 38=7x-3x+6 | | m=4(2x+6) | | 2x-22y=14 | | p^2=3p+4 | | 12/x=x^2 | | H(t)=-16t^2+12t+25 | | 5x-1+5x=-81 | | (-16t^2)+24t+9=18t | | 50=100-5x | | 18=2x-6x+2 | | -58=5x-8 | | 3/4x-3.2=5.3-2/3x | | 119y-98x+840=0 | | 3^-3/3^6 | | x=4.33+1.667y | | 3x(squared)+x+2=0 | | 6y-8=7y-1 | | 15w^2-13w+2=0 | | 4.8-7.6=1.2+15.8 | | 3cosx=sinx-1 | | ([(x^1/4)(y^2/5)]^20)/x^2 | | 4/9y-12=1/4y- | | 4/9y-12=1/4y-4 | | 36-95d-72-4d+7+3d= |

Equations solver categories