Step-by-step explanation:

Answer:
The which spends on the piano is( 50 minutes )
The which spends on the guitar is( 40 minutes )
Step-by-step explanation:
The steps of the solution in the above photo
I hope that is useful for you :)
Answer:
85%
Step-by-step explanation:
If she got 3 wrong then it means she got 20-3 right, so she got 17 questions right.
From there we get the fraction: 17/20
To make the a percentage we times both the top and bottom by 5 (because 20 x 5 = 100)
By doing that we get 17x5/20x5
= 85/100
That is equal to 85%
(Sorry I could only answer part A) The Answer is 84 -w-
hookes law gives the equation F=kx where F is the elastic force and k is the constant and x or small e is extension if we draw a graph you'll see that the graph increases by the same ratio every single time hence giving a straight line show that they are F and x are propotional to a certain limit