College Math!!! I did the first half of the question, I just need the bottom half of it.

Which value of c would make he following expression completely factored? 8x+cy

Leo has b boxes of pencils. each box contains 6 pencils. he has a total of 42 pencils. the equation that represents this situation the value of b that makes the equation true the first one is b+6=42,6b=42,b=42+6,or 42b=6 the second one are 7,836 48

Which point lies on a circle with a radius of 5 units and center at p(6, 1)?