2r(5-r)=13+2r

Simple and best practice solution for 2r(5-r)=13+2r 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 2r(5-r)=13+2r equation:


Simplifying
2r(5 + -1r) = 13 + 2r
(5 * 2r + -1r * 2r) = 13 + 2r
(10r + -2r2) = 13 + 2r

Solving
10r + -2r2 = 13 + 2r

Solving for variable 'r'.

Reorder the terms:
-13 + 10r + -2r + -2r2 = 13 + 2r + -13 + -2r

Combine like terms: 10r + -2r = 8r
-13 + 8r + -2r2 = 13 + 2r + -13 + -2r

Reorder the terms:
-13 + 8r + -2r2 = 13 + -13 + 2r + -2r

Combine like terms: 13 + -13 = 0
-13 + 8r + -2r2 = 0 + 2r + -2r
-13 + 8r + -2r2 = 2r + -2r

Combine like terms: 2r + -2r = 0
-13 + 8r + -2r2 = 0

Begin completing the square.  Divide all terms by
-2 the coefficient of the squared term: 

Divide each side by '-2'.
6.5 + -4r + r2 = 0

Move the constant term to the right:

Add '-6.5' to each side of the equation.
6.5 + -4r + -6.5 + r2 = 0 + -6.5

Reorder the terms:
6.5 + -6.5 + -4r + r2 = 0 + -6.5

Combine like terms: 6.5 + -6.5 = 0.0
0.0 + -4r + r2 = 0 + -6.5
-4r + r2 = 0 + -6.5

Combine like terms: 0 + -6.5 = -6.5
-4r + r2 = -6.5

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 = -6.5 + 4

Reorder the terms:
4 + -4r + r2 = -6.5 + 4

Combine like terms: -6.5 + 4 = -2.5
4 + -4r + r2 = -2.5

Factor a perfect square on the left side:
(r + -2)(r + -2) = -2.5

Can't calculate square root of the right side.

The solution to this equation could not be determined.

See similar equations:

| -5(w-7)+9w+2= | | 4(3-4y)+7y=3 | | 10a=-20 | | 2x+5x=6x-6 | | 3z=-33 | | 2(7x+6)=14x+12 | | 0.20(y-5)+0.14y=0.18y-0.6 | | 16-(2m+6)=4+4m-12 | | 3x^2-4=-23 | | 0.20x+0.45(70)=42.5 | | 8b^2-5=123 | | -3=5x | | -3.6b-7.2=12.7-6.1b | | -6v^2=-300 | | -7y-11=5y+13 | | y^2+10t+25= | | 7x+5=-4+2x+19 | | 46+3x=(-8+6x)+26 | | 2b+180.4=56*8 | | -2(2x+3)=-11x+6 | | 10n^2-8=752 | | 13-5(a+2)=9+a | | y-7=6 | | .50x+.50(40)=.25(80) | | 8(x+5)-9=31 | | -13=8 | | .50x+10=.75x+6 | | A^2-9=27 | | 6X+6/3=4x-5 | | 12-(6x+7)=9-5x | | 38.7m=309.6 | | 8x+5/7=9x+1/7 |

Equations solver categories