You get everything you need from factoring the last expression:

The left side is a difference of squares, and we get another difference of squares upon factoring. We end up with

Plug in everything you know and solve for
:

If you would do this in whole number form, it'll be 40/7.
P(A) = P(8) + P(9) + P(10) = 3/10 so P(A complement) = 1 - P(A) = 1 - 3/10 = 7/10 - D
Hi!
1. Your answer should be the first option. (It looks the best to me)
2. it is the last option because it's the only one that's identical to the original picture.
3. It should be the third option since there are 10cm on the top of the shape.
4. a total of 39
Hope that helps, good luck! :)
Answer:
Stohr sequence
Step-by-step explanation:
Let a_1=1 and define a_(n+1) to be the least integer greater than a_n which cannot be written as the sum of at most h>=2 addends among the terms a_1, a_2, ..., a_n. This defines the h-Stöhr sequence