7y^2-8y-7=0

Simple and best practice solution for 7y^2-8y-7=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 7y^2-8y-7=0 equation:


Simplifying
7y2 + -8y + -7 = 0

Reorder the terms:
-7 + -8y + 7y2 = 0

Solving
-7 + -8y + 7y2 = 0

Solving for variable 'y'.

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

Divide each side by '7'.
-1 + -1.142857143y + y2 = 0

Move the constant term to the right:

Add '1' to each side of the equation.
-1 + -1.142857143y + 1 + y2 = 0 + 1

Reorder the terms:
-1 + 1 + -1.142857143y + y2 = 0 + 1

Combine like terms: -1 + 1 = 0
0 + -1.142857143y + y2 = 0 + 1
-1.142857143y + y2 = 0 + 1

Combine like terms: 0 + 1 = 1
-1.142857143y + y2 = 1

The y term is -1.142857143y.  Take half its coefficient (-0.5714285715).
Square it (0.3265306123) and add it to both sides.

Add '0.3265306123' to each side of the equation.
-1.142857143y + 0.3265306123 + y2 = 1 + 0.3265306123

Reorder the terms:
0.3265306123 + -1.142857143y + y2 = 1 + 0.3265306123

Combine like terms: 1 + 0.3265306123 = 1.3265306123
0.3265306123 + -1.142857143y + y2 = 1.3265306123

Factor a perfect square on the left side:
(y + -0.5714285715)(y + -0.5714285715) = 1.3265306123

Calculate the square root of the right side: 1.151751107

Break this problem into two subproblems by setting 
(y + -0.5714285715) equal to 1.151751107 and -1.151751107.

Subproblem 1

y + -0.5714285715 = 1.151751107 Simplifying y + -0.5714285715 = 1.151751107 Reorder the terms: -0.5714285715 + y = 1.151751107 Solving -0.5714285715 + y = 1.151751107 Solving for variable 'y'. Move all terms containing y to the left, all other terms to the right. Add '0.5714285715' to each side of the equation. -0.5714285715 + 0.5714285715 + y = 1.151751107 + 0.5714285715 Combine like terms: -0.5714285715 + 0.5714285715 = 0.0000000000 0.0000000000 + y = 1.151751107 + 0.5714285715 y = 1.151751107 + 0.5714285715 Combine like terms: 1.151751107 + 0.5714285715 = 1.7231796785 y = 1.7231796785 Simplifying y = 1.7231796785

Subproblem 2

y + -0.5714285715 = -1.151751107 Simplifying y + -0.5714285715 = -1.151751107 Reorder the terms: -0.5714285715 + y = -1.151751107 Solving -0.5714285715 + y = -1.151751107 Solving for variable 'y'. Move all terms containing y to the left, all other terms to the right. Add '0.5714285715' to each side of the equation. -0.5714285715 + 0.5714285715 + y = -1.151751107 + 0.5714285715 Combine like terms: -0.5714285715 + 0.5714285715 = 0.0000000000 0.0000000000 + y = -1.151751107 + 0.5714285715 y = -1.151751107 + 0.5714285715 Combine like terms: -1.151751107 + 0.5714285715 = -0.5803225355 y = -0.5803225355 Simplifying y = -0.5803225355

Solution

The solution to the problem is based on the solutions from the subproblems. y = {1.7231796785, -0.5803225355}

See similar equations:

| 3(X+2)(2x-10)=0 | | 8x^2=26x+357 | | .81t^2+140=0 | | 4+(-3)2= | | (x+5)=(3x-1) | | -0.3-2.7=-4.1 | | B+8=2 | | 5(r+3)=4+2r+2 | | x-2.3=6.4 | | 750=y+(y*.07) | | 15-3x=7x+5 | | 6cos-1=2 | | 4(q)=52 | | 2(4x+1)=3x-9x | | 1996.43x=7385-67x | | R-(-5)=9 | | 8(4-n)+2=90 | | 44221=a*2+b | | 2(5x+7)+3=10x+17 | | 2x-17=2x-12 | | 3(r+7)=15 | | 4r-1=-4+4r+3 | | -4(x+9)=7-3x | | 2(4x-10)=46 | | 3m+3=5 | | -15+3=-2(x+7) | | 1996+43x=3716 | | 3x+3=(x+3) | | 10(a-2)=-70 | | -86=-7n+4(-n-5) | | 7-3x-5-3x=5 | | Kx-3x=-2+5k |

Equations solver categories