1: 11/28
2: 67/72
3: 1 11/30
Is this from khan academy?
Answer: 
Step-by-step explanation:
We have the following polynomial:

This is a polynomial of the form
. Following this rule to expand it, we have:


Applying common factor
:

Note the polynomial inside the parenthesis is a perfect square trinomial, which can be factored to
. Hence, the final simplification is:

12(8+t) You do what's in the parenthesis first, then multiply by 12, or in other words multiply 12 by the sum of 8 and t.