Step-by-step explanation:
Given
The function is 
for
, we will check the values of
and 
Take 3 and 4

Similarly,

Thus, 
Also,
is 1 i.e. a constant value. So, the function is increasing linearly for the given interval.
Answer:
No this is not correct question for me but I am not sure what to
Answer:
The total amount without tax is $141.57
Step-by-step explanation:
Since the coupon is 10% off, they would only have to pay 90% of what they would before (this is before tax). To find out the total after the coupon you would find 90% of 157.30. (This is the longer but better explainable/showable way)
157.30 / 100 = 1.573 (this is 1%)
1.573 * 90 = 141.57
Therefore the answer is $141.57
Connected cellular because you make 800 a week but with the other you only make 700