Answer:
Explanation:
we are given the equation a+b-c=180
Now to solve it for c we need to isolate the c
first step can be addition of c to both side
a+b-c+c=180+c
a+b=180+c
now in second step we subtract 180 from both sides to get
a+b-180=180+c-180
a+b-180 = c
c= a+b-180