Y=0.5(x-3)(x+3)

Solution for Y=0.5(x-3)(x+3) equation:

Simplifying
Y = 0.5(x + -3)(x + 3)

Reorder the terms:
Y = 0.5(-3 + x)(x + 3)

Reorder the terms:
Y = 0.5(-3 + x)(3 + x)

Multiply (-3 + x) * (3 + x)
Y = 0.5(-3(3 + x) + x(3 + x))
Y = 0.5((3 * -3 + x * -3) + x(3 + x))
Y = 0.5((-9 + -3x) + x(3 + x))
Y = 0.5(-9 + -3x + (3 * x + x * x))
Y = 0.5(-9 + -3x + (3x + x2))

Combine like terms: -3x + 3x = 0
Y = 0.5(-9 + 0 + x2)
Y = 0.5(-9 + x2)
Y = (-9 * 0.5 + x2 * 0.5)
Y = (-4.5 + 0.5x2)

Solving
Y = -4.5 + 0.5x2

Solving for variable 'Y'.

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

Simplifying
Y = -4.5 + 0.5x2