Answer:
14n - 29
Step-by-step explanation:
First you'd distribute in the parentheses by -5. -5 × -2.4n and -5 × 4 which you would get 12 and -20.
Then, bring everything down and combine like terms. 2n + 12n = 14n || -9 - 20 or -9 - (-20) = -29. 14n - 29 is the lowest you can simplify because you can subtract a variable and a constant together.
Given that the associative property of multiplication says that you can group the numbers in any combination, we can reorganize the expression as: 7·(10·3)=210. So the answer would be the first option.
1 millimetre = 1/1000 = 1×10^-3 m
Answer: The average age is 7.1 years.
This problem is an example of when we need to take a weighted average. We simply can't just find the average of 5 and 8, because there are different children of each each.
To start, lets multiply the total number of children by their individual ages.
6 x 5 = 30 years
14 x 8 = 112 years
There are 142 years among the 20 years, so divide 142 by 20. This gives us an average age of 7.1 years.
