7X-4=6X-4-X
7X-6X+X=0
2X=0
X=0
<h3>
Answer: 139.5</h3>
Work Shown:
cos(angle) = adjacent/hypotenuse
cos(55) = 80/x
x*cos(55) = 80
x = 80/cos(55)
x = 139.4757 approximately
x = 139.5
There are 5 letters in the word "prime"
Imagine we had 5 slots to fill. They are empty initially.
Slot 1 has 5 choices to pick from
Once we pick a letter, we have 4 choices left over for slot 2
Slot 3 will have 3 choices
Slot 4 will have 2 choices
Slot 5 will have 1 choice
We have this countdown: 5,4,3,2,1
which multiplies out to 5*4*3*2*1 = 120
There are 120 unique ways to arrange the letters. Order matters. Because order matters, this is a permutation.