8r^2-16r-40=0

Simple and best practice solution for 8r^2-16r-40=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 8r^2-16r-40=0 equation:


Simplifying
8r2 + -16r + -40 = 0

Reorder the terms:
-40 + -16r + 8r2 = 0

Solving
-40 + -16r + 8r2 = 0

Solving for variable 'r'.

Factor out the Greatest Common Factor (GCF), '8'.
8(-5 + -2r + r2) = 0

Ignore the factor 8.

Subproblem 1

Set the factor '(-5 + -2r + r2)' equal to zero and attempt to solve: Simplifying -5 + -2r + r2 = 0 Solving -5 + -2r + r2 = 0 Begin completing the square. Move the constant term to the right: Add '5' to each side of the equation. -5 + -2r + 5 + r2 = 0 + 5 Reorder the terms: -5 + 5 + -2r + r2 = 0 + 5 Combine like terms: -5 + 5 = 0 0 + -2r + r2 = 0 + 5 -2r + r2 = 0 + 5 Combine like terms: 0 + 5 = 5 -2r + r2 = 5 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 = 5 + 1 Reorder the terms: 1 + -2r + r2 = 5 + 1 Combine like terms: 5 + 1 = 6 1 + -2r + r2 = 6 Factor a perfect square on the left side: (r + -1)(r + -1) = 6 Calculate the square root of the right side: 2.449489743 Break this problem into two subproblems by setting (r + -1) equal to 2.449489743 and -2.449489743.

Subproblem 1

r + -1 = 2.449489743 Simplifying r + -1 = 2.449489743 Reorder the terms: -1 + r = 2.449489743 Solving -1 + r = 2.449489743 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 = 2.449489743 + 1 Combine like terms: -1 + 1 = 0 0 + r = 2.449489743 + 1 r = 2.449489743 + 1 Combine like terms: 2.449489743 + 1 = 3.449489743 r = 3.449489743 Simplifying r = 3.449489743

Subproblem 2

r + -1 = -2.449489743 Simplifying r + -1 = -2.449489743 Reorder the terms: -1 + r = -2.449489743 Solving -1 + r = -2.449489743 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 = -2.449489743 + 1 Combine like terms: -1 + 1 = 0 0 + r = -2.449489743 + 1 r = -2.449489743 + 1 Combine like terms: -2.449489743 + 1 = -1.449489743 r = -1.449489743 Simplifying r = -1.449489743

Solution

The solution to the problem is based on the solutions from the subproblems. r = {3.449489743, -1.449489743}

Solution

r = {3.449489743, -1.449489743}

See similar equations:

| 7+3x=53 | | 8x+7x-7x-72=48-9x | | 6x-10=4x+80 | | 7p-3p+4=-4-2+10 | | 12z+4=2(5z+8)-1 | | -3=7-a | | h^2-h-50=22 | | 0=-9x^2+42x-49 | | 800=100x-.5x^2-(40x+800) | | 8x-5+3=2x-4 | | n^3+9n^2+8n=0 | | 10(k-5)+3(5-k)= | | 6w+8=6(w+3)-10 | | X^4x=0 | | 10*n+6=-24 | | 18-2p=8p-13 | | xdy+ydx+xy(3dx+dy)=0 | | 2x=27-8x | | -4+4(x-2)=12x+6-8x | | 6x-4y-2x+8y=4x+4y | | 2.01c-6=0.15c+6.96 | | 7(n-4)=2n-8 | | 6x+7(-2x-8)=16 | | 5(w-7)=15 | | -18x+-26y=-124 | | 9y=7+5y | | z/7+19=3.5 | | 6x-5+2x=4 | | 2g+9g+70=180 | | 4x+5=2x-2x+9 | | 5h+2-5h=22 | | 6x-46=73 |

Equations solver categories