y(3-4y)=7+4(8-y)

Solution for y(3-4y)=7+4(8-y) equation:

Simplifying
y(3 + -4y) = 7 + 4(8 + -1y)
(3 * y + -4y * y) = 7 + 4(8 + -1y)
(3y + -4y2) = 7 + 4(8 + -1y)
3y + -4y2 = 7 + (8 * 4 + -1y * 4)
3y + -4y2 = 7 + (32 + -4y)

Combine like terms: 7 + 32 = 39
3y + -4y2 = 39 + -4y

Solving
3y + -4y2 = 39 + -4y

Solving for variable 'y'.

Reorder the terms:
-39 + 3y + 4y + -4y2 = 39 + -4y + -39 + 4y

Combine like terms: 3y + 4y = 7y
-39 + 7y + -4y2 = 39 + -4y + -39 + 4y

Reorder the terms:
-39 + 7y + -4y2 = 39 + -39 + -4y + 4y

Combine like terms: 39 + -39 = 0
-39 + 7y + -4y2 = 0 + -4y + 4y
-39 + 7y + -4y2 = -4y + 4y

Combine like terms: -4y + 4y = 0
-39 + 7y + -4y2 = 0

Begin completing the square.  Divide all terms by
-4 the coefficient of the squared term: 

Divide each side by '-4'.
9.75 + -1.75y + y2 = 0

Move the constant term to the right:

Add '-9.75' to each side of the equation.
9.75 + -1.75y + -9.75 + y2 = 0 + -9.75

Reorder the terms:
9.75 + -9.75 + -1.75y + y2 = 0 + -9.75

Combine like terms: 9.75 + -9.75 = 0.00
0.00 + -1.75y + y2 = 0 + -9.75
-1.75y + y2 = 0 + -9.75

Combine like terms: 0 + -9.75 = -9.75
-1.75y + y2 = -9.75

The y term is -1.75y.  Take half its coefficient (-0.875).
Square it (0.765625) and add it to both sides.

Add '0.765625' to each side of the equation.
-1.75y + 0.765625 + y2 = -9.75 + 0.765625

Reorder the terms:
0.765625 + -1.75y + y2 = -9.75 + 0.765625

Combine like terms: -9.75 + 0.765625 = -8.984375
0.765625 + -1.75y + y2 = -8.984375

Factor a perfect square on the left side:
(y + -0.875)(y + -0.875) = -8.984375

Can't calculate square root of the right side.

The solution to this equation could not be determined.