Question 243049
You start by factoring the equation:
{{{y = x^2 + 2x - 48}}}
We can mentally test factors of 48 that have are two apart. We quickly recall that 6 * 8 = 48.  And we know they have to have opposite signs to get to -48 as a product.  So we have:
{{{y = (x + 8)(x - 6)}}}
when x = -8, y =0
when x = 6, y = 0
when x = 0, y = -48