When a quadratic is in intercept form, it is in the most factored, simplified form. So, to “undo” the factoring, we will need to multiply the two binomials using the FOIL method.
FOIL means First Outer Inner Last, which means when we are given two binomials multiplying each other, we first distribute the outer term first, then the inner term last. Here’s how we do it:
Given y=(x+2)(x-2)
Using FOIL:
y=(x•x-2•x)+(2•x-2•2)
So, we took x from (x+2) and multiplied every term in (x-2) by it, then did the same for 2 in (x+2).
Let’s simplify:
y=x^2-2x+2x-4
We can combine like terms:
y=x^2-4
*Notice that -2x+2x canceled out; this is because they contain inverse operations. For example, -2+2=0 or -2(4)+2(4)=-8+8=0.
Your final equation is y=x^2-4
*Note that ^ symbol represents an exponent, so x^2 means x squared or to the second power.