Answer:
(a) 9
(b) -2
Step-by-step explanation:
it is very important to start by finding the equation of the line then substitute in some values.
Correct answer is option D.The solution is listed below
He is incorrect because each number is in a different place and those different places are worth more or less than the other places
Answer:
$159.95
Step-by-step explanation:
Let price of trumphet be defined by 
price of clarinet = $139.95
Number of clarinets sold = 19
Earning through clarinets' sale = 
Total earning of store = $4578.45
Earning through trumphets' sale = 
price of one trumohet = 
price of clarinet = $159.95