Answer:

4. f = 78,   g= 7/2

5. m=4,   n=5

6. k = 2,    j=9/2

Step-by-step explanation:

4. consecutive angles of parallelogram are supplementary so,

  f + 30 + 72 = 180

                   f = 180 -72-30

                   f = 78

 opposite sides are equal so,

8g - 3 = 25

     8g = 28

       g = 28/8 0r 7/2

5. diagonals of parallelogram bisect each other, meaning they are equal, so

m + 8 = 3m                2n-1=9

    2m=8                       2n=10

       m= 4                        n=5

6.   6k = k + 10         5j-9=3j

     5k = 10                   2j=9

       k = 2                        j=9/2