5r^2-20r-9=6

Simple and best practice solution for 5r^2-20r-9=6 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 5r^2-20r-9=6 equation:


Simplifying
5r2 + -20r + -9 = 6

Reorder the terms:
-9 + -20r + 5r2 = 6

Solving
-9 + -20r + 5r2 = 6

Solving for variable 'r'.

Reorder the terms:
-9 + -6 + -20r + 5r2 = 6 + -6

Combine like terms: -9 + -6 = -15
-15 + -20r + 5r2 = 6 + -6

Combine like terms: 6 + -6 = 0
-15 + -20r + 5r2 = 0

Factor out the Greatest Common Factor (GCF), '5'.
5(-3 + -4r + r2) = 0

Ignore the factor 5.

Subproblem 1

Set the factor '(-3 + -4r + r2)' equal to zero and attempt to solve: Simplifying -3 + -4r + r2 = 0 Solving -3 + -4r + r2 = 0 Begin completing the square. Move the constant term to the right: Add '3' to each side of the equation. -3 + -4r + 3 + r2 = 0 + 3 Reorder the terms: -3 + 3 + -4r + r2 = 0 + 3 Combine like terms: -3 + 3 = 0 0 + -4r + r2 = 0 + 3 -4r + r2 = 0 + 3 Combine like terms: 0 + 3 = 3 -4r + r2 = 3 The r term is -4r. Take half its coefficient (-2). Square it (4) and add it to both sides. Add '4' to each side of the equation. -4r + 4 + r2 = 3 + 4 Reorder the terms: 4 + -4r + r2 = 3 + 4 Combine like terms: 3 + 4 = 7 4 + -4r + r2 = 7 Factor a perfect square on the left side: (r + -2)(r + -2) = 7 Calculate the square root of the right side: 2.645751311 Break this problem into two subproblems by setting (r + -2) equal to 2.645751311 and -2.645751311.

Subproblem 1

r + -2 = 2.645751311 Simplifying r + -2 = 2.645751311 Reorder the terms: -2 + r = 2.645751311 Solving -2 + r = 2.645751311 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '2' to each side of the equation. -2 + 2 + r = 2.645751311 + 2 Combine like terms: -2 + 2 = 0 0 + r = 2.645751311 + 2 r = 2.645751311 + 2 Combine like terms: 2.645751311 + 2 = 4.645751311 r = 4.645751311 Simplifying r = 4.645751311

Subproblem 2

r + -2 = -2.645751311 Simplifying r + -2 = -2.645751311 Reorder the terms: -2 + r = -2.645751311 Solving -2 + r = -2.645751311 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '2' to each side of the equation. -2 + 2 + r = -2.645751311 + 2 Combine like terms: -2 + 2 = 0 0 + r = -2.645751311 + 2 r = -2.645751311 + 2 Combine like terms: -2.645751311 + 2 = -0.645751311 r = -0.645751311 Simplifying r = -0.645751311

Solution

The solution to the problem is based on the solutions from the subproblems. r = {4.645751311, -0.645751311}

Solution

r = {4.645751311, -0.645751311}

See similar equations:

| 3w(11w+8)= | | 5r^2-20r-9=0 | | 13.62+.13(x+3)=14.37-.09x | | xsquare(x+5)(x-5)=0 | | 1600x=20 | | 3y+17=62 | | y+19=192 | | f(-6)=7-2x | | 4x+14=5x | | 2x=6(2x-2)-5 | | 13.62+.13(x+3)=14.37+.09x | | 3(3+1)=(9-2x) | | 6n=(n+5) | | 30=-8x+2(x-6) | | y=mx+bfindx | | x^1/4=2 | | 5x-15=2x+20 | | 90+3+x+x-8=180 | | 10n-0.75=0.1n-0.375 | | 2-7g=2-g | | 2e^3x-9=0 | | 12a=3a+2.5a+a | | -1=6x-31 | | 15.93+.09(x+3)=16.43-.13x | | -3(3y-7)+2(2y+8)= | | 2[-2(4x+5)+4(3x-4)]= | | z/3=11 | | 5x-7=2x-14 | | 7/3.7/5 | | 51=50 | | (x/3)-9= | | -7y-12w=29 |

Equations solver categories