Not really Specific in asking in what way you want it answered... So here is what Im able to understand.
Function
Joseph : 20 + .23x = y
Micki : 10 + .15x =y
Hope this is what your asking...
Treat it just like and equation at first. Multiply the 10 on both sides to get rid of it, leaving you with 50
x. Then on the number line, since there is a line under it, you would make a filled in circle and an arrow pointing towards 51 and beyond
The answer will be Negative
Answer: Yes, it is a real number. 3.4 is a rational number and rational numbers are real numbers. So 3.4 is a real number.