y=-(2x+1)(x-4)

Solution for y=-(2x+1)(x-4) equation:

Simplifying
y = -1(2x + 1)(x + -4)

Reorder the terms:
y = -1(1 + 2x)(x + -4)

Reorder the terms:
y = -1(1 + 2x)(-4 + x)

Multiply (1 + 2x) * (-4 + x)
y = -1(1(-4 + x) + 2x * (-4 + x))
y = -1((-4 * 1 + x * 1) + 2x * (-4 + x))
y = -1((-4 + 1x) + 2x * (-4 + x))
y = -1(-4 + 1x + (-4 * 2x + x * 2x))
y = -1(-4 + 1x + (-8x + 2x2))

Combine like terms: 1x + -8x = -7x
y = -1(-4 + -7x + 2x2)
y = (-4 * -1 + -7x * -1 + 2x2 * -1)
y = (4 + 7x + -2x2)

Solving
y = 4 + 7x + -2x2

Solving for variable 'y'.

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

Simplifying
y = 4 + 7x + -2x2