2y^2-21y+8=0

Simple and best practice solution for 2y^2-21y+8=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 2y^2-21y+8=0 equation:


Simplifying
2y2 + -21y + 8 = 0

Reorder the terms:
8 + -21y + 2y2 = 0

Solving
8 + -21y + 2y2 = 0

Solving for variable 'y'.

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

Divide each side by '2'.
4 + -10.5y + y2 = 0

Move the constant term to the right:

Add '-4' to each side of the equation.
4 + -10.5y + -4 + y2 = 0 + -4

Reorder the terms:
4 + -4 + -10.5y + y2 = 0 + -4

Combine like terms: 4 + -4 = 0
0 + -10.5y + y2 = 0 + -4
-10.5y + y2 = 0 + -4

Combine like terms: 0 + -4 = -4
-10.5y + y2 = -4

The y term is -10.5y.  Take half its coefficient (-5.25).
Square it (27.5625) and add it to both sides.

Add '27.5625' to each side of the equation.
-10.5y + 27.5625 + y2 = -4 + 27.5625

Reorder the terms:
27.5625 + -10.5y + y2 = -4 + 27.5625

Combine like terms: -4 + 27.5625 = 23.5625
27.5625 + -10.5y + y2 = 23.5625

Factor a perfect square on the left side:
(y + -5.25)(y + -5.25) = 23.5625

Calculate the square root of the right side: 4.85412196

Break this problem into two subproblems by setting 
(y + -5.25) equal to 4.85412196 and -4.85412196.

Subproblem 1

y + -5.25 = 4.85412196 Simplifying y + -5.25 = 4.85412196 Reorder the terms: -5.25 + y = 4.85412196 Solving -5.25 + y = 4.85412196 Solving for variable 'y'. Move all terms containing y to the left, all other terms to the right. Add '5.25' to each side of the equation. -5.25 + 5.25 + y = 4.85412196 + 5.25 Combine like terms: -5.25 + 5.25 = 0.00 0.00 + y = 4.85412196 + 5.25 y = 4.85412196 + 5.25 Combine like terms: 4.85412196 + 5.25 = 10.10412196 y = 10.10412196 Simplifying y = 10.10412196

Subproblem 2

y + -5.25 = -4.85412196 Simplifying y + -5.25 = -4.85412196 Reorder the terms: -5.25 + y = -4.85412196 Solving -5.25 + y = -4.85412196 Solving for variable 'y'. Move all terms containing y to the left, all other terms to the right. Add '5.25' to each side of the equation. -5.25 + 5.25 + y = -4.85412196 + 5.25 Combine like terms: -5.25 + 5.25 = 0.00 0.00 + y = -4.85412196 + 5.25 y = -4.85412196 + 5.25 Combine like terms: -4.85412196 + 5.25 = 0.39587804 y = 0.39587804 Simplifying y = 0.39587804

Solution

The solution to the problem is based on the solutions from the subproblems. y = {10.10412196, 0.39587804}

See similar equations:

| x*8-63=x*6-5 | | -3u+5(u-6)=-28 | | X^2-8=4 | | 15-x=2(2x+6) | | -49x^2+21x+28=0 | | y+10=32 | | -3(x-4y)= | | 2x+(5x+40)=360 | | 4x-2y+3x+2y= | | 32x+1=33 | | 7t+10-11t^2=0 | | 3x^3-30x+63=0 | | 30=6y+6(y+3) | | y=(0.25x+3)(0.75x+1) | | -x^2+2+3=0 | | 2x^2-17=2x(x+7)-3(4x+1) | | P-(p-q)=q | | 3y-2=-2y-37 | | (3x+13)(3x-5)=-24 | | x^2=400-10x | | 2(e^6x+10)=13e^3x | | 6+55x=44x+14 | | 11t^2=7t+10 | | 4x+25=42 | | a^2+28a+192=0 | | (3m+8)(2m-5)=0 | | -9y=-19 | | 2y+y+3x+5y= | | 6x+7=38-3x | | 8abc-7b-7c+8=5b+5c+1 | | 9x+7(.50)=14.75 | | 5-3z-2z^2=0 |

Equations solver categories