What are 2 equivalent fractions for 7/21

Determine whether the quadrilateral below is a parallelogram. justify/explain your answer (this means back it up! give specific information that supports your decision. writing just "yes" or "no" will result in no credit.)

For a field trip to the zoo, 4 students rode in cars and the rest filled nine busess. how many students were in each bus if 472 students were on the trip

What are the solutions of the equation? 5z^2 + 9z - 2 = 0 a. 1, -2 b. 1, 2 c. 1/5, -2 d. 1/5, 2