Sum/difference:
Let
This means that
Now, assume that 
is rational. The sum/difference of two rational numbers is still rational (so 5-x is rational), and the division by 3 doesn't change this. So, you have that the square root of 8 equals a rational number, which is false. The mistake must have been supposing that was rational, which proves that the sum/difference of the two given terms was irrational
Multiplication/division:
The logic is actually the same: if we multiply the two terms we get
if again we assume x to be rational, we have
But if x is rational, so is -x/15, and again we come to a contradiction: we have the square root of 8 on one side, which is irrational, and -x/15 on the other, which is rational. So, again, x must have been irrational. You can prove the same claim for the division in a totally similar fashion.
The answer choice is B. 50 dollars per month.
50 times 3 is 150 and 50 times 6 is 300.
Answer:
in (x,y), it becomes (-x,y)
Step-by-step explanation:
Answer:
See below.
Step-by-step explanation:
For each size, divide the cost by the amount. Make sure the amounts are all in the same units. Then, the lowest cost per unit is the best buy.
