Given four sets: A, B, C, and D. Each set has elements which are represented by the following expressions. In all of them, ∈ (x is an element of Natural numbers) ● Set A 2 − 1, 1≤≤10
● Set B 2, 1≤≤10
● Set C 2 , 1≤≤7
● Set D 3, 1≤≤9
a) Create an appropriate Venn diagram for sets A, B, C, and D. Make sure to explain your reasoning.

b) What is the value of (∪∪∪)?

the one on the bottom left

step-by-step explanation:

all of the other ones have a specific pattern

a.   since the profit made in 2012 is equal to the profit made in 2014, the profit is symmetric about the line y = 120,000.

step-by-step explanation:

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.