25.748=2*3.14*r^2+2*3.14*r*3.1

Simple and best practice solution for 25.748=2*3.14*r^2+2*3.14*r*3.1 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 25.748=2*3.14*r^2+2*3.14*r*3.1 equation:


Simplifying
25.748 = 2 * 3.14r2 + 2 * 3.14r * 3.1

Multiply 2 * 3.14
25.748 = 6.28r2 + 2 * 3.14r * 3.1

Reorder the terms for easier multiplication:
25.748 = 6.28r2 + 2 * 3.14 * 3.1r

Multiply 2 * 3.14
25.748 = 6.28r2 + 6.28 * 3.1r

Multiply 6.28 * 3.1
25.748 = 6.28r2 + 19.468r

Reorder the terms:
25.748 = 19.468r + 6.28r2

Solving
25.748 = 19.468r + 6.28r2

Solving for variable 'r'.

Reorder the terms:
25.748 + -19.468r + -6.28r2 = 19.468r + -19.468r + 6.28r2 + -6.28r2

Combine like terms: 19.468r + -19.468r = 0.000
25.748 + -19.468r + -6.28r2 = 0.000 + 6.28r2 + -6.28r2
25.748 + -19.468r + -6.28r2 = 6.28r2 + -6.28r2

Combine like terms: 6.28r2 + -6.28r2 = 0.00
25.748 + -19.468r + -6.28r2 = 0.00

Begin completing the square.  Divide all terms by
-6.28 the coefficient of the squared term: 

Divide each side by '-6.28'.
-4.1 + 3.1r + r2 = 0

Move the constant term to the right:

Add '4.1' to each side of the equation.
-4.1 + 3.1r + 4.1 + r2 = 0 + 4.1

Reorder the terms:
-4.1 + 4.1 + 3.1r + r2 = 0 + 4.1

Combine like terms: -4.1 + 4.1 = 0.0
0.0 + 3.1r + r2 = 0 + 4.1
3.1r + r2 = 0 + 4.1

Combine like terms: 0 + 4.1 = 4.1
3.1r + r2 = 4.1

The r term is 3.1r.  Take half its coefficient (1.55).
Square it (2.4025) and add it to both sides.

Add '2.4025' to each side of the equation.
3.1r + 2.4025 + r2 = 4.1 + 2.4025

Reorder the terms:
2.4025 + 3.1r + r2 = 4.1 + 2.4025

Combine like terms: 4.1 + 2.4025 = 6.5025
2.4025 + 3.1r + r2 = 6.5025

Factor a perfect square on the left side:
(r + 1.55)(r + 1.55) = 6.5025

Calculate the square root of the right side: 2.55

Break this problem into two subproblems by setting 
(r + 1.55) equal to 2.55 and -2.55.

Subproblem 1

r + 1.55 = 2.55 Simplifying r + 1.55 = 2.55 Reorder the terms: 1.55 + r = 2.55 Solving 1.55 + r = 2.55 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '-1.55' to each side of the equation. 1.55 + -1.55 + r = 2.55 + -1.55 Combine like terms: 1.55 + -1.55 = 0.00 0.00 + r = 2.55 + -1.55 r = 2.55 + -1.55 Combine like terms: 2.55 + -1.55 = 1 r = 1 Simplifying r = 1

Subproblem 2

r + 1.55 = -2.55 Simplifying r + 1.55 = -2.55 Reorder the terms: 1.55 + r = -2.55 Solving 1.55 + r = -2.55 Solving for variable 'r'. Move all terms containing r to the left, all other terms to the right. Add '-1.55' to each side of the equation. 1.55 + -1.55 + r = -2.55 + -1.55 Combine like terms: 1.55 + -1.55 = 0.00 0.00 + r = -2.55 + -1.55 r = -2.55 + -1.55 Combine like terms: -2.55 + -1.55 = -4.1 r = -4.1 Simplifying r = -4.1

Solution

The solution to the problem is based on the solutions from the subproblems. r = {1, -4.1}

See similar equations:

| 5a+10b=450 | | 453.6672=2*3.14*r^2+2*3.14*r*13 | | 5b+10a=450 | | -1-0.28v=2 | | 5*26=x | | -5+3(6-x)=1 | | 4x*3=99+x | | 20x=.6 | | 10a+5b=450 | | -2(6p-5)+2p=8p-8 | | 2(0,3x-1)-0,6=4+0,1x | | 8+10y=9y-6 | | -16t^2+57=0 | | 17x=6x-22 | | 138-4x=32x+22 | | 10.5=3b-12.5 | | 4x+2x+96-22=88+4x | | 6-3x-5x-1=10 | | 4(3x-44)=4(2x-10) | | 4x^4-17x^2+18=0 | | 5x*3+17=69+2x | | -2(3x-4)+12=8 | | -16t^2+7.85t+57=0 | | 4-x-2-x=x | | 5x^2+4xy-12y^2=0 | | 4-x-2+x=x | | 189.028=2*3.14*r^2+2*3.14*r*2.7 | | 6a+8b=1500 | | 3t-6=2t+2 | | -3x+8=-1 | | (3x*7)=21 | | 4x+2+7x-19=180 |

Equations solver categories