Answer:
4x + 1
Step-by-step explanation:
note that (f + g)(x) = f(x) + g(x) , thus
f(x) + g(x)
= x + 3x + 1 ← collect like terms
= 4x + 1
Answer: C) For every original price, there is exactly one sale price.
For any function, we always have any input go to exactly one output. The original price is the input while the output is the sale price. If we had an original price of say $100, and two sale prices of $90 and $80, then the question would be "which is the true sale price?" and it would be ambiguous. This is one example of how useful it is to have one output for any input. The input in question must be in the domain.
As the table shows, we do not have any repeated original prices leading to different sale prices.
The X (1) axis represents the number of hours, and the Y (75) axis represents the number of dollars. When 0 hours are passed, 0 hours are payed (0,0) 1 hour 75 dollars are payed (1, 75) 2 hours 150 dollars is payed (2, 150) and so on