What do you have to do to make two fractions equivalent?

The graph shows the prices of different numbers of bushels of corn at a store in the current year. the table shows the prices of different numbers of bushels of corn at the same store in the previous year. previous year number of bushels price of corn (dollars) 2 10 4 20 6 30 8 40 part a: describe in words how you can find the rate of change of a bushel of corn in the current year, and find the value. part b: how many dollars more is the price of a bushel of corn in the current year than the price of a bushel of corn in the previous year? show your work.

Which one ? is the answer and how to find this answer

In trapezoid abcd, ac is a diagonal and ∠abc≅∠acd. find ac if the lengths of the bases bc and ad are 12m and 27m respectively.