Adding rational numbers involves adding decimals and repeating decimals like 4.6666666..... Whole numbers on the other hand involves adding 7+6 which arent exactly decimals
<span>6x-2y=-8
-2y =-6x-8
y = 3x+4
y= 3x+4</span>
Answer:
a. closed under addition and multiplication
b. not closed under addition but closed under multiplication.
c. not closed under addition and multiplication
d. closed under addition and multiplication
e. not closed under addition but closed under multiplication
Step-by-step explanation:
a.
Let A be a set of all integers divisible by 5.
Let ∈A such that
Find
So, is divisible by 5.
So,
is divisible by 5.
Therefore, A is closed under addition and multiplication.
b.
Let A = { 2n +1 | n ∈ Z}
Let ∈A such that where m, n ∈ Z.
Find
So,
∉ A
So,
∈ A
Therefore, A is not closed under addition but A is closed under multiplication.
c.
Let but ∉A
Also,
∉A
Therefore, A is not closed under addition and multiplication.
d.
Let A = { 17n: n∈Z}
Let ∈ A such that
Find x + y and xy
So,
∈ A
Therefore, A is closed under addition and multiplication.
e.
Let A be the set of nonzero real numbers.
Let ∈ A such that
Find x + y
So,
∈ A
Also, if x and y are two nonzero real numbers then xy is also a non-zero real number.
Therefore, A is not closed under addition but A is closed under multiplication.
Answer:
Gianna makes $18 per hour.
Step-by-step explanation:
Given Gianna makes 90$ for 5 hours. That means she should make $ = 18$ every hour.
Therefore we have:
a.
HOURS DOLLARS
1 18
2 36
3 54
4 72
5 90
6 108
7 126
b.
For the tabular column mark Hours on the x - axis and Dollars on the Y - axis. It can be plotted from the above table easily.
c.
If Gianna works for 8 hours she would have made 8 X 18 = 144$.
So, she will earn 144$ in 8 hours.
d.
To make 60$ she would have to work hours = 3.33 hours.