True or false, a proportional relationship has a constant rate of change

For the chance to be team captain, the numbers 1-30 are put in a hat and you get two chances to pick a number, without replacement. which formula correctly shows how to find the probability that you choose the number 1 and then 2?

Which equation is equivalent to the given expression? -(1/2y+1/4) a. -1/4(1+2y) b. 1/4(2y-1) c. -2(1/4y-1/8) d. 2(1/8-1/4y)

What is the gcf of 20c^3-5c^4+30c^6