Which whole number is equal to 21/7

Find the greatest common factor of 28 and 35

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

If f(x) = 6x – 4, what is f(x) when x = 8? a2 b16 c44 d52