42 (1- 25/100) = 63/2 = 31.5 dollars
answer is $31.50
hope it helps
6.5 + 7.6
8.4 + 5.7
ur welcome
Using the critical point concept, it is found that a = -3 and b = 7.
<h3>What are the critical points of a function?</h3>
- The critical points of a function are the values of x for which:

In this problem, the function is:

Hence, the derivative is:

Then:







Since the critical point is at x = 2, we have that:




Then:

Critical point at (2,3) means that when
, then:



You can learn more about the critical point concept at brainly.com/question/2256078
The answer maybe C ) cylinder =200pie and cone = 80pie