400 : 1kg
400 : 1000
1 : 2.5
n = 2.5
Answer:
It's a valid sample because the first five people were selected to participate.
Step-by-step explanation:
True because random people who saw the advertisement responded. By chance, not every person who saw the advertisement answered, therefore it was random, but it would be more random if he decided to reject the second, fourth, sixth, and eighth person, and only the first, third, fifth, seventh, and ninth were chosen.
Answer: -7y+8x
Step-by-step explanation: I assume you mean to simplify
Step 1: Remove parentheses : -4y - x - (3y - 9x)
Step 2: -(3y - 9x) = -3y + 9x
Step 3: Simplify: -4y - x - 3y +9x
Step 4: Answer: -7y+8x
Use the formula SA=a+1/2ps
a=area of the base
p= perimeter of the base
s= slant height
