Lol that’s why not I just got to tell
Answer:
The expression that represents his total time is given by "t = 7.5/s" where s is his speed against the wind.
Step-by-step explanation:
In order to solve this problem we will assign a variable to Curtis speed on the first leg of the trip, this will be called "s". Since the speed on the first part is "s" and the speed on the second part is 20% higher, then the speed on the second part is "1.2s". Each leg of the course is 9 miles long, therefore the time it took to go each way is given by:
time = distance/speed
First part:
t1 = 9/s
Second part:
t2 = 9/1.2s = 7.5/s
The expression for the whole course is the sum of each, so we have:
t = t1 + t2
t = 9/s + 7.5/s
t = (9 + 7.5)/s = (16.5)/s
Answer:

Step-by-step explanation:
Given equation is
………………(1)
we use derivative formula 


And also apply 'u v' formula

Differentiating equation (1) partially with respective to 'x' , we treated 'y' as constant.
( here y treated as constant so the derivative of constant function is zero in addition but in multiplication the constant is keep as like 'y').
on simplification , we get

again simplification, we get

taking common '
on left on side , we get

dividing '
on both sides, we get

<u>Final answer</u>:-

75 is my answer and this is a guess so if its right tell me