Answer:
The domain is the set of x values for which the function resides in.
In this graph, it is unclear as to if the function goes on to infinity, but if it does, the answer is quite easily:
(-2, 4] and [7, ∞)
since the function starts on the left at -2 then continues to the right, with a pause, then indefinitely after.
First off, let's convert the percentages to decimal format, so our 77% turns to 77/100 or 0.77, and our 55% turns to 55/100 or 0.55 and so on
now, the sum of both salines, must add up to the 77% mixture, let's say is "y"
so, 11 + 4 = y, and whatever the concentration level is, must also sum up to the mixture's concentration of 77%
anyway thus

solve for "x"
Sample space for all possible outcomes:
HH, HT, TH, TT
Sample space for event where heads is the first toss:
HT, HH
(3^3)* (3^-3)= 3^0
Remember that if you have the same base, add the exponents.
3^0=1
5(1)=5
Final answer: 5
Are there any multiple choice answers?