I honestly dont know how to figure this one out.
Distribute the two to each of the values in the parentheses.
-4 +6a-10= 1-1a
Then move like terms to the same side to simplify.
6a+1a=1+10+4
7a=15
a=15/7
35 Degrees. This is because the a straight line is 180 degrees. Knowing this, 180-100= 80. 80+65= 145. 180-145=35 which is the missing angle.
19 is the median of the numbers
