Can you please help me with this​

Factor the expression using the gcf. the expression 21m−49n factored using the gcf

Aregular pentagon with a perimeter of 21 inches is dilated by a scale factor of 5/3 to create a new pentagon. what is the perimeter of the new pentagon?

Which of the following are arithmetic sequences? check all that apply. a. 0.3, 0.6, 0.9, 1.2, 1.5, b. 2, 3, 6, 11, 18, c. 150, 147, 144, 142, d. 2, 4, 9, 16, 25,