Is "ab" an angle? If so, can you try to repost the picture because I cannot see anything so it's hard to try and help you.
Answer: y= 2 • (1/3)^x-2 -2
hope this helps!
X - the number
you double the number - 2x
you subtract the result from five - 5-2x
you get negative one - 5-2x=-1

The number is 3.
The equation of this line would be y=-2x+3. I hope this helps! Could I possibly get brainliest?
21, 15, 30
a+b+c=66
c=2b; a=b+6
(b+6)+b+(2b)=66
-6 -6
(b)+b+(2b)=60
2b+2b=60
4b =60
(1/4) 4b = (1/4)60
b= 15, which is the second number