What numbers are multiples of 7 and factors of 28

The multiples of 7. 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98, 105, 112, 119, 126, 133, 140, 147, 154, 161, 168, and more 

These are all factors of 28. Let's list out the factors of 28: 1, 2, 4, 7, 14, 28. Each of the numbers in this list are factor pairs. We can move from the outsides to the center and pair the numbers together to make sets of numbers that will multiply to make 28.

12+3b -1=-5-b -12-1+5=-b-3b -8=-4b