Question

How do you find the value of the variable in this problem?

Answer 1

Since the opposite angles of parallelogram are equal:
$4a - 4 = 2a + 30$
$4a - 2a = 30 + 4$
$2a=34$
$a=34/2=17$

Answer 2

You would do 2(4a-4) + 2(2a+30)=8a-8+4a+60=12a+52
12a+52=360
12a=308
a=25 2/3