r^2+8r-2=2

Simple and best practice solution for r^2+8r-2=2 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+8r-2=2 equation:


Simplifying
r2 + 8r + -2 = 2

Reorder the terms:
-2 + 8r + r2 = 2

Solving
-2 + 8r + r2 = 2

Solving for variable 'r'.

Reorder the terms:
-2 + -2 + 8r + r2 = 2 + -2

Combine like terms: -2 + -2 = -4
-4 + 8r + r2 = 2 + -2

Combine like terms: 2 + -2 = 0
-4 + 8r + r2 = 0

Begin completing the square.

Move the constant term to the right:

Add '4' to each side of the equation.
-4 + 8r + 4 + r2 = 0 + 4

Reorder the terms:
-4 + 4 + 8r + r2 = 0 + 4

Combine like terms: -4 + 4 = 0
0 + 8r + r2 = 0 + 4
8r + r2 = 0 + 4

Combine like terms: 0 + 4 = 4
8r + r2 = 4

The r term is 8r.  Take half its coefficient (4).
Square it (16) and add it to both sides.

Add '16' to each side of the equation.
8r + 16 + r2 = 4 + 16

Reorder the terms:
16 + 8r + r2 = 4 + 16

Combine like terms: 4 + 16 = 20
16 + 8r + r2 = 20

Factor a perfect square on the left side:
(r + 4)(r + 4) = 20

Calculate the square root of the right side: 4.472135955

Break this problem into two subproblems by setting 
(r + 4) equal to 4.472135955 and -4.472135955.

Subproblem 1

r + 4 = 4.472135955 Simplifying r + 4 = 4.472135955 Reorder the terms: 4 + r = 4.472135955 Solving 4 + r = 4.472135955 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '-4' to each side of the equation. 4 + -4 + r = 4.472135955 + -4 Combine like terms: 4 + -4 = 0 0 + r = 4.472135955 + -4 r = 4.472135955 + -4 Combine like terms: 4.472135955 + -4 = 0.472135955 r = 0.472135955 Simplifying r = 0.472135955

Subproblem 2

r + 4 = -4.472135955 Simplifying r + 4 = -4.472135955 Reorder the terms: 4 + r = -4.472135955 Solving 4 + r = -4.472135955 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '-4' to each side of the equation. 4 + -4 + r = -4.472135955 + -4 Combine like terms: 4 + -4 = 0 0 + r = -4.472135955 + -4 r = -4.472135955 + -4 Combine like terms: -4.472135955 + -4 = -8.472135955 r = -8.472135955 Simplifying r = -8.472135955

Solution

The solution to the problem is based on the solutions from the subproblems. r = {0.472135955, -8.472135955}

See similar equations:

| n/7-14=21 | | m^2+10m-34=5 | | 5x^2+8=41x | | -5x-42+12x=77 | | 10+3x=2(3+4x) | | n^2+8n-2=2 | | 5(x+2)-3(x+4)=2 | | x^2+15x=9x | | 3/4y=2x-6 | | p^2-8p-12=8 | | 18-x=3x+2 | | 3x^2+100x-2500=0 | | 2(x-6)=y-14 | | x^2+6x-35=6 | | 2x^2+1x=-10x-15 | | 8x-(5x+8)=4 | | 24+3*(-6)=-18+18 | | 8.79x+100=77.2641+10x | | n^2-8n-30=-5 | | 6.74x+49=45.4276+7x | | 2x+43=6x+7 | | 9x^4y/36^3y^2 | | 18x^2-12x-6=0 | | 2x-12=8x+4 | | 33.8=r^2+7.5r | | 12-5(x+4)=11-4(x+5) | | 11x-180-2x=90 | | 30x-(-x+6)+(-5x+9)=-(5x+6)+(-8+3x) | | 48h^2-16h+1=0 | | 4-x/3=1 | | 1e+65e= | | X-48=30 |

Equations solver categories