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.
Answer:
75% of the data will reside in the range 23000 to 28400.
Step-by-step explanation :
To find the range of values :
We need to find the values that deviate from the mean. Since we want at least 75% of the data to reside between the range therefore we have,
Solving this, we would get k = 2 which shows the value one needs to find lies outside the range.
Range is given by : mean +/- (z score) × (value of a standard deviation)
⇒ Range : 25700 +/- 2 × 1350
⇒ Range : (25700 - 2700) to (25700 + 2700)
Hence, 75% of the data will reside in the range 23000 to 28400.
12 red counters
7 more red counters than yellow counters
12 - 7 = 5 yellow counters
Dara has 5 yellow counters.
Answer: A horseshoe weighs 8.2 ounces The nails in the horseshoe weigh 0.12 ounces.
Step-by-step explanation: B should be your answer have a great day :)
