<span>−1.2z − 8.2 > −9.7</span>
−1.2z > - 1.5
z < 1.25
Answer:
P43=4!(4–3)!=241=24
Step-by-step explanation:
There are four choices you can make for the lead reindeer. For each possible choice, there are then three remaining you can choose to fly second, making 4×3=12 choices for the lead pair. For each possible choice there are two remaining reindeer to take up the back position, making 12×2=24 choices for the team of three.
This type of problem is called a permutation problem, and we write Pnr for the number of ways of choosing r items from n possibilities when the order of the items matters. In this case we are choosing 3 reindeer from 4 possibilities, and the order they appear in the flying line does matter, so the answer we want is P43. The general formula is Pnr=n!(n−r)!. For the answer we are looking for we therefore have:
P43=4!(4–3)!=241=24
So, first, what are the two sides?
let's call then x and y
we know that 2(x+y)=12.5 (that's the distance around)
so that means that x+y=6.25 (I just divided both by 2)
now, x=4y (from "4 times as long as it is wide")
so we can substitute:
x+4x=6.25
5x=6.25
x=1.25
so one side, is 1.25 and the other will be 1.25*4=5
and for the area we multiply the two:
1.25*5=6.25 square kilometers, and this is the answer!