r^2-18r+56=0-4

Simple and best practice solution for r^2-18r+56=0-4 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^2-18r+56=0-4 equation:


Simplifying
r2 + -18r + 56 = 0 + -4

Reorder the terms:
56 + -18r + r2 = 0 + -4

Combine like terms: 0 + -4 = -4
56 + -18r + r2 = -4

Solving
56 + -18r + r2 = -4

Solving for variable 'r'.

Reorder the terms:
56 + 4 + -18r + r2 = -4 + 4

Combine like terms: 56 + 4 = 60
60 + -18r + r2 = -4 + 4

Combine like terms: -4 + 4 = 0
60 + -18r + r2 = 0

Begin completing the square.

Move the constant term to the right:

Add '-60' to each side of the equation.
60 + -18r + -60 + r2 = 0 + -60

Reorder the terms:
60 + -60 + -18r + r2 = 0 + -60

Combine like terms: 60 + -60 = 0
0 + -18r + r2 = 0 + -60
-18r + r2 = 0 + -60

Combine like terms: 0 + -60 = -60
-18r + r2 = -60

The r term is -18r.  Take half its coefficient (-9).
Square it (81) and add it to both sides.

Add '81' to each side of the equation.
-18r + 81 + r2 = -60 + 81

Reorder the terms:
81 + -18r + r2 = -60 + 81

Combine like terms: -60 + 81 = 21
81 + -18r + r2 = 21

Factor a perfect square on the left side:
(r + -9)(r + -9) = 21

Calculate the square root of the right side: 4.582575695

Break this problem into two subproblems by setting 
(r + -9) equal to 4.582575695 and -4.582575695.

Subproblem 1

r + -9 = 4.582575695 Simplifying r + -9 = 4.582575695 Reorder the terms: -9 + r = 4.582575695 Solving -9 + r = 4.582575695 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '9' to each side of the equation. -9 + 9 + r = 4.582575695 + 9 Combine like terms: -9 + 9 = 0 0 + r = 4.582575695 + 9 r = 4.582575695 + 9 Combine like terms: 4.582575695 + 9 = 13.582575695 r = 13.582575695 Simplifying r = 13.582575695

Subproblem 2

r + -9 = -4.582575695 Simplifying r + -9 = -4.582575695 Reorder the terms: -9 + r = -4.582575695 Solving -9 + r = -4.582575695 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '9' to each side of the equation. -9 + 9 + r = -4.582575695 + 9 Combine like terms: -9 + 9 = 0 0 + r = -4.582575695 + 9 r = -4.582575695 + 9 Combine like terms: -4.582575695 + 9 = 4.417424305 r = 4.417424305 Simplifying r = 4.417424305

Solution

The solution to the problem is based on the solutions from the subproblems. r = {13.582575695, 4.417424305}

See similar equations:

| x-39+3x=33 | | m+5=2m-1 | | 5(-2n+1)+3n=-23 | | 5(1+-2n)+3n=-23 | | 4x-3*5x-3=5x+5-8x-32 | | c^2=b^2+a^2 | | 3.7x-50=2.1x+6 | | 2x+4(4x+5)=-70 | | 4y+2y-1=15 | | m=1+-2n | | X^2-2x=35+2x | | -0.02x=-1.4 | | 2(-4+x)=22 | | -33=-7x+3x+3 | | -10x-13y=-45 | | 25y^2-x^2=0 | | -6(-4x+5)-6x=6(x-6)-2 | | X^3+3x-4=50 | | 0=20(x^2+12x-20) | | y-5.7=1 | | x^8=90000000 | | 5y^3-6y+1=0 | | 15-5x=21 | | 5[3(6-y)-4(8+3y)]-132=-6[5(6+3y)-3] | | log(x)+log(9)=1 | | x^2+6=-8x+12 | | x^3-9x^2+20x-5=0 | | 198=5+193 | | cos(5*x)=0 | | -4(w+1)=4w-1+2(5w+6) | | N+(n+2)=224 | | c^2=b^2a^2 |

Equations solver categories