r^2+18.5r-36=0

Simple and best practice solution for r^2+18.5r-36=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 r^2+18.5r-36=0 equation:


Simplifying
r2 + 18.5r + -36 = 0

Reorder the terms:
-36 + 18.5r + r2 = 0

Solving
-36 + 18.5r + r2 = 0

Solving for variable 'r'.

Begin completing the square.

Move the constant term to the right:

Add '36' to each side of the equation.
-36 + 18.5r + 36 + r2 = 0 + 36

Reorder the terms:
-36 + 36 + 18.5r + r2 = 0 + 36

Combine like terms: -36 + 36 = 0
0 + 18.5r + r2 = 0 + 36
18.5r + r2 = 0 + 36

Combine like terms: 0 + 36 = 36
18.5r + r2 = 36

The r term is 18.5r.  Take half its coefficient (9.25).
Square it (85.5625) and add it to both sides.

Add '85.5625' to each side of the equation.
18.5r + 85.5625 + r2 = 36 + 85.5625

Reorder the terms:
85.5625 + 18.5r + r2 = 36 + 85.5625

Combine like terms: 36 + 85.5625 = 121.5625
85.5625 + 18.5r + r2 = 121.5625

Factor a perfect square on the left side:
(r + 9.25)(r + 9.25) = 121.5625

Calculate the square root of the right side: 11.025538536

Break this problem into two subproblems by setting 
(r + 9.25) equal to 11.025538536 and -11.025538536.

Subproblem 1

r + 9.25 = 11.025538536 Simplifying r + 9.25 = 11.025538536 Reorder the terms: 9.25 + r = 11.025538536 Solving 9.25 + r = 11.025538536 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '-9.25' to each side of the equation. 9.25 + -9.25 + r = 11.025538536 + -9.25 Combine like terms: 9.25 + -9.25 = 0.00 0.00 + r = 11.025538536 + -9.25 r = 11.025538536 + -9.25 Combine like terms: 11.025538536 + -9.25 = 1.775538536 r = 1.775538536 Simplifying r = 1.775538536

Subproblem 2

r + 9.25 = -11.025538536 Simplifying r + 9.25 = -11.025538536 Reorder the terms: 9.25 + r = -11.025538536 Solving 9.25 + r = -11.025538536 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '-9.25' to each side of the equation. 9.25 + -9.25 + r = -11.025538536 + -9.25 Combine like terms: 9.25 + -9.25 = 0.00 0.00 + r = -11.025538536 + -9.25 r = -11.025538536 + -9.25 Combine like terms: -11.025538536 + -9.25 = -20.275538536 r = -20.275538536 Simplifying r = -20.275538536

Solution

The solution to the problem is based on the solutions from the subproblems. r = {1.775538536, -20.275538536}

See similar equations:

| x^2+14x-80=0 | | 12=7/10g-44 | | t^2-12t=-19 | | 4x^2-31x+53=-3x+8 | | h^2-14h-11=0 | | 48000=x-.1x | | 6x^2-49X-45= | | 16g-4=32 | | a^2-150+56=0 | | r^2-18r=13 | | 3=9x-244 | | 50=x-(.1)x | | 7,5-x=2 | | 1/4x+7=29 | | sin(0.8)=sin(-x) | | 7w/5-7/3=-2w+2/3 | | 7x+40=2x-10findx | | x-8,1=2,9 | | 07x+0.09(20000-x)=1550 | | y=-x^2-10x-21 | | x=4-12x | | 3x+90+110+110=720 | | 9(7-2x)=4(3x+5) | | -2=5x-y | | 6p^2/2p^2 | | 7x=4-3x | | 8(5+y)-5y=13 | | x^2+11x+17=2x-1 | | x-3,5=4,8 | | x-(3x-4)=3-(3)(3) | | k-11=24-9k | | -6w/5-5/3=2w/5-2 |

Equations solver categories