F(x)=-2e^x
x=3
f(3)=-2e^3
pemdas so exponents first
e^3
e=2.718281828454590
cube that
20.0855
now we have
-2 times 20.0855=-40.1711
answer should be -40.1711
(I see what you did wrong, if -6=-2 times e^3, divide -2, 3=e^3, maybe you just put -2 times 3 by mistake)
Im guessing it would be about 50 degrees
When you divide 1722 by 6 you get 287 so it's not a repeating number so if you estimate 287 to 290 then you get 1740 so your answer is 287.