Because you cannot add the two numbers you must find a common denominator for 16 and 20. This answer is 4. The greatest number of group members possible is 4.
Answer: Choice C. 
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Explanation:
The domain is the set of all allowed x inputs.
Here we see that x = -3 is the smallest x value possible as it is from the left-most point. The graph goes on forever to the right, so there is no largest x value. Effectively infinity is the largest x value even though infinity is not a number.
We can say the domain is
which can be simplified to
or 
In short: x can be -3 or larger.
The measure of a straight line is 180
125+30=155
180-155=25
x = 25