8r^2-40r-122=0

Simple and best practice solution for 8r^2-40r-122=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^2-40r-122=0 equation:


Simplifying
8r2 + -40r + -122 = 0

Reorder the terms:
-122 + -40r + 8r2 = 0

Solving
-122 + -40r + 8r2 = 0

Solving for variable 'r'.

Factor out the Greatest Common Factor (GCF), '2'.
2(-61 + -20r + 4r2) = 0

Ignore the factor 2.

Subproblem 1

Set the factor '(-61 + -20r + 4r2)' equal to zero and attempt to solve: Simplifying -61 + -20r + 4r2 = 0 Solving -61 + -20r + 4r2 = 0 Begin completing the square. Divide all terms by 4 the coefficient of the squared term: Divide each side by '4'. -15.25 + -5r + r2 = 0 Move the constant term to the right: Add '15.25' to each side of the equation. -15.25 + -5r + 15.25 + r2 = 0 + 15.25 Reorder the terms: -15.25 + 15.25 + -5r + r2 = 0 + 15.25 Combine like terms: -15.25 + 15.25 = 0.00 0.00 + -5r + r2 = 0 + 15.25 -5r + r2 = 0 + 15.25 Combine like terms: 0 + 15.25 = 15.25 -5r + r2 = 15.25 The r term is -5r. Take half its coefficient (-2.5). Square it (6.25) and add it to both sides. Add '6.25' to each side of the equation. -5r + 6.25 + r2 = 15.25 + 6.25 Reorder the terms: 6.25 + -5r + r2 = 15.25 + 6.25 Combine like terms: 15.25 + 6.25 = 21.5 6.25 + -5r + r2 = 21.5 Factor a perfect square on the left side: (r + -2.5)(r + -2.5) = 21.5 Calculate the square root of the right side: 4.636809248 Break this problem into two subproblems by setting (r + -2.5) equal to 4.636809248 and -4.636809248.

Subproblem 1

r + -2.5 = 4.636809248 Simplifying r + -2.5 = 4.636809248 Reorder the terms: -2.5 + r = 4.636809248 Solving -2.5 + r = 4.636809248 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '2.5' to each side of the equation. -2.5 + 2.5 + r = 4.636809248 + 2.5 Combine like terms: -2.5 + 2.5 = 0.0 0.0 + r = 4.636809248 + 2.5 r = 4.636809248 + 2.5 Combine like terms: 4.636809248 + 2.5 = 7.136809248 r = 7.136809248 Simplifying r = 7.136809248

Subproblem 2

r + -2.5 = -4.636809248 Simplifying r + -2.5 = -4.636809248 Reorder the terms: -2.5 + r = -4.636809248 Solving -2.5 + r = -4.636809248 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '2.5' to each side of the equation. -2.5 + 2.5 + r = -4.636809248 + 2.5 Combine like terms: -2.5 + 2.5 = 0.0 0.0 + r = -4.636809248 + 2.5 r = -4.636809248 + 2.5 Combine like terms: -4.636809248 + 2.5 = -2.136809248 r = -2.136809248 Simplifying r = -2.136809248

Solution

The solution to the problem is based on the solutions from the subproblems. r = {7.136809248, -2.136809248}

Solution

r = {7.136809248, -2.136809248}

See similar equations:

| -16x-4x=-3 | | 10z*z= | | -8-31x+4x^2=0 | | 21=x-6 | | 0+5y=14 | | 5z^2-22z+8= | | -30y+9=-20y-9 | | 100f+10=75f+90 | | 2x^2-7x+4k=0 | | 5ln(2x)=10 | | -2x+2(0)=0 | | 4*(x-3)-16=5*(x-5) | | ln(7x)=y | | -2(0)+2y=0 | | 3x^3-x^2+9x=0 | | 3cos(x)+5sin(x)=1 | | 3x^5-x^2+9x=0 | | 0=9/8x-5 | | 3(a+b)-2(a-b)= | | 4y+24=3x | | -5w-6=2w-9 | | (2sin(x)+1)(2cos(x)+3)=0 | | Y=9/8(0)-5 | | 4(q+3)=3 | | (cos(x)-1)(sin(x)+1)=0 | | 220+2b=180+4b | | 3cosx+5sinx=1 | | 125+600x=725 | | 3cosx+5cosx=1 | | (9/4-225)x-2=-2 | | 1+0.0625*x^2=40 | | -7/2x-5(0)=2 |

Equations solver categories