Hi there!
The perimeter is when you add all the sides of a shape. In a rectangle, two sides are the same, and so are the other two. So, if the two sides are 2x-3 and x+2 the expression will be:
2(2x-3) + 2(x+2)
If we were to simplify this, it would be
4x-6+2x+4
6x-2
Hope this helps!
Alright here it is:
-2/7x + y = -7
Let's think of an example which would better help visualize this situation.
1) Someone exercises a lot so they can concentrate more on their homework (here running and concentration on homework are dependent events)
2) Someone exercises a lot because they wear a blue t-shirt (here, you can clearly see that wearing a blue shirt and exercising are not related. These events are independent).
Now concentrating on P(a | b) = Probability a occurred if b occurred.
It does not matter if b occurred (just like it didn't matter that the person wore a blue shirt which meant that they exercised) for the outcome a to occur.
Therefore, probability of P(a | b) = P(a)
P(a | b) = 0.65
Hope I helped :)
