ABCD is a parallelogram. Determine the value of a.

Answer:
a = 6
Step-by-step explanation:
The opposite sides of a parallelogram are congruent , so
BA = CD , that is
7a - 3 = 3 + 6a ( subtract 6a from both sides )
a - 3 = 3 ( add 3 to both sides )
a = 6