I think its b because of its relation to the base
(3x +3) (x - 4)
3x(x - 4) + 3(x - 4)
3x^2 - 12x + 3x - 12
3x^2 - 9x - 12
FInd the common denominator: 12
That means gianni ate 4/12 of his pizza
Subtract 9/12 by 4/12
You get 5/12
That means 5/12 must be your answer
Richard ate 5/12 of his pizza
Hope this helped
(Answer also can be 5)
