y=y^2-4

Simple and best practice solution for y=y^2-4 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 y=y^2-4 equation: 


Simplifying
y = y2 + -4

Reorder the terms:
y = -4 + y2

Solving
y = -4 + y2

Solving for variable 'y'.

Reorder the terms:
4 + y + -1y2 = -4 + y2 + 4 + -1y2

Reorder the terms:
4 + y + -1y2 = -4 + 4 + y2 + -1y2

Combine like terms: -4 + 4 = 0
4 + y + -1y2 = 0 + y2 + -1y2
4 + y + -1y2 = y2 + -1y2

Combine like terms: y2 + -1y2 = 0
4 + y + -1y2 = 0

Begin completing the square.  Divide all terms by
-1 the coefficient of the squared term: 

Divide each side by '-1'.
-4 + -1y + y2 = 0

Move the constant term to the right:

Add '4' to each side of the equation.
-4 + -1y + 4 + y2 = 0 + 4

Reorder the terms:
-4 + 4 + -1y + y2 = 0 + 4

Combine like terms: -4 + 4 = 0
0 + -1y + y2 = 0 + 4
-1y + y2 = 0 + 4

Combine like terms: 0 + 4 = 4
-1y + y2 = 4

The y term is y.  Take half its coefficient (0.5).
Square it (0.25) and add it to both sides.

Add '0.25' to each side of the equation.
-1y + 0.25 + y2 = 4 + 0.25

Reorder the terms:
0.25 + -1y + y2 = 4 + 0.25

Combine like terms: 4 + 0.25 = 4.25
0.25 + -1y + y2 = 4.25

Factor a perfect square on the left side:
(y + 0.5)(y + 0.5) = 4.25

Calculate the square root of the right side: 2.061552813

Break this problem into two subproblems by setting 
(y + 0.5) equal to 2.061552813 and -2.061552813.


Subproblem 1
y + 0.5 = 2.061552813

Simplifying
y + 0.5 = 2.061552813

Reorder the terms:
0.5 + y = 2.061552813

Solving
0.5 + y = 2.061552813

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-0.5' to each side of the equation.
0.5 + -0.5 + y = 2.061552813 + -0.5

Combine like terms: 0.5 + -0.5 = 0.0
0.0 + y = 2.061552813 + -0.5
y = 2.061552813 + -0.5

Combine like terms: 2.061552813 + -0.5 = 1.561552813
y = 1.561552813

Simplifying
y = 1.561552813


Subproblem 2
y + 0.5 = -2.061552813

Simplifying
y + 0.5 = -2.061552813

Reorder the terms:
0.5 + y = -2.061552813

Solving
0.5 + y = -2.061552813

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-0.5' to each side of the equation.
0.5 + -0.5 + y = -2.061552813 + -0.5

Combine like terms: 0.5 + -0.5 = 0.0
0.0 + y = -2.061552813 + -0.5
y = -2.061552813 + -0.5

Combine like terms: -2.061552813 + -0.5 = -2.561552813
y = -2.561552813

Simplifying
y = -2.561552813


Solution
The solution to the problem is based on the solutions
from the subproblems.
y = {1.561552813, -2.561552813}

See similar equations:

| (-20+d)= | | 4x-13x=54 | | 3x+33+2x=57 | | x^24=17*24x^9+6942*41321 | | 3x+10=385 | | 8(11/12)-1(5/6)= | | 2x-4x=2 | | x+18=3x+10 | | x+18=30+3x | | x^3+x^2+21x-45=0 | | 5x+x-17=163 | | 871.9=(1/3)3.14*49h | | 5d-2-(5-2d)= | | 4d-3-(4-7d)= | | 4d-3-(4-7d)d= | | 4d-3-(4-7d)=0 | | 31.4=2*3.14r | | 31.4=2*3.14 | | 0=8-2x | | (4s-2)(5s-4)=0 | | (17x+)(12.x+1)= | | 153=(1/2)h(8+9) | | 102=(1/2)h(8+9) | | -7x+9=86 | | 37y-x=126 | | 8(m-5)=7x+4 | | -x=43 | | Y=37-126x | | -13+12x-3x^2=0 | | 19+[x-1]=33 | | 7x+y=10solvery | | 7n-8=68 |

Equations solver categories