Answer:
a = -21
Step-by-step explanation:
x=10
It's a 90 degree angle.
90-60=30
30=the remaining angle, 3x
x=30/3, or 10
Hope I helped!
6a + 5a = 11
6a + 5a=
11a
11a = 11
divide both side by 11
11a/11 = 11/11
a = 1