How do you FOIL (3x - 4)(7x + 7)(3x4)(7x+7)?

1 Answer
Jun 1, 2015

(a+b)(c+d)=ac+ad+bc+bd(a+b)(c+d)=ac+ad+bc+bd
(3x-4)(7x+7)=3x*7x+3x*7-4*7x-4*7(3x4)(7x+7)=3x7x+3x747x47
(3x-4)(7x+7)=21x²+21x-28x-28
(3x-4)(7x+7)=21x²-7x-28

You can factorize by seven : (3x-4)(7x+7)=7(3x²-x-4)