Answer:

Step-by-step explanation:
Given



Required
List out the sample space
To do this, we simply pick 1 item in each category, without repetition.
So, we have:

Answer:
Step-by-step explanation:
BC=AD
3x-1=x+5
3x-x=5+1
2x=6
x=3
BC=3×3-1=8
CD=2x=2×3=6
perimeter=2(8+6)=2(14)=28
Answer:
0.234
Step-by-step explanation:
Let S be the sum,
S = 2 + 4 + 6 + ... + 2 (n - 2) + 2 (n - 1) + 2n
Reverse the order of terms:
S = 2n + 2 (n - 1) + 2 (n - 2) + ... + 6 + 4 + 2
Add up terms in the same positions, so that twice the sum is
2S = (2n + 2) + (2n + 2) + (2n + 2) + ... + (2n + 2)
or
2S = n (2n + 2)
Divide both sides by 2 to solve for S :
S = n (n + 1)