It is a right triangle. If it contains the 90°, it is definitely a right triangle.
6.8 * 10^10 is the answer
1) 6-2= a/4
4*4=a
2) x/4= -5+6
x/4=1
x=1*4
3) 9x=-7+7
x=0/9
4) -4=n/5
5*-4=n
5) 5-4=r/20
20*1=r
6) 6*-1= 5+x
-5-6=x
7) v+9=8*3
v=24-9
8)2n+10=-2
2n=-2-10
n=-12/2
9) -your work is wrong because a negative with another negative is an addition-
-9x+1=-80
-9x=-80+(-1)
-9x= -81
x=-81/-9
x=9
10)-6=n/2-10
10-6=n/2
2*4=n
11)-2=2+v/4
-2+(-2)=v/4
4*-4=v
12) 144=-12x-60
204=-12x
204/-12=x
