The greatest common factor of the 3 listed numbers, is 12.
This can be found by simply writing out all the factors of each number. 24's factors are: 1,2,3,4,6,8,12,24 60's factors are: 1,2,3,4,5,6,10,12,15,20,30,60 84's factors are: 1,2,3,4,6,7,12,14,21,42,84 The highest factor shown is 12.
The difference (subtraction) of 6 times a number (x represents number) and 7. This gives us 6x-7. That is equal to five times (multiplication) the sum (addition) of the number, x, and 4. This gives you = 5(x+4) and combined gives us B, 6x-7=5(x+4).
