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
no it is not simplified because there are two y values
The y-intercept of the line is 40