Consider the substitution,
so that the integral is equivalent to
Notice that
which means 
is odd, so
Perhaps more work than necessary, but it does make it easier to see that the original integrand exhibits some symmetry about 
.
Well actually when i did this equation i got y=3 so you might want to recheck your answer and take another look at the steps you took.
Hopefully this helped you ^0^
Answer:
The total number of possible outcomes if the code has 3 letters is 64
Step-by-step explanation:
The keypad has only the letters A-D, that is, A,B,C,D.
To calculate the total number of possible outcomes if the code has 3 letters,
let these spaces represent the code _ _ _
For the first space, there are 4 possibilities (since we have 4 letters)
For the second space, we also have 4 possibilities (since there is no restriction on repetition)
Also, we have 4 possibilities for the last space.
Hence, the total number of possible outcomes if the code has 3 letters is 4×4×4 = 4³ = 64.
D cause 51+51=102 because yeah I think thats how you do it
40% more food is needed to feed the other cat so they are using 80% of the food
