Aquadratic equation is written in four equivalent forms below.
i. y = x(x + 6) - 8(x + 6)
ii. y = (x - 1)2 - 49
iii. y = x2 - 2x - 48
iv. y = (x + 6)(x - 8)
which of the forms shown above would be the most useful if attempting to find the y-intercept of the quadratic equation?