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:
117 cups
Step-by-step explanation:
two dozen cookies calls for 234cups of sugar
2 dozen cookies = 234 cups of sugar
How much sugar is needed to make one dozen cookies?
Let x = cups of sugar needed
1 dozen cookies = x cups of sugar
2 dozen cookies : 234 cups of sugar = 1 dozen cookies : x cups of sugar
2 : 234 = 1 : x
2 / 234 = 1 / x
Cross product
2*x = 234 * 1
2x = 234
x = 234 / 2
= 117 cups
Your options are wrong because none corresponds with the answer
Answer:
Z-7
6-7
-1
Step-by-step explanation:
we have to replace the value of Z and then subtract by seven.
Answer:
sin(A-B) = 24/25
Step-by-step explanation:
The trig identity for the differnce of angles tells you ...
sin(A -B) = sin(A)cos(B) -sin(B)cos(A)
We are given that sin(A) = 4/5 in quadrant II, so cos(A) = -√(1-(4/5)^2) = -3/5.
And we are given that cos(B) = 3/5 in quadrant I, so sin(B) = 4/5.
Then ...
sin(A-B) = (4/5)(3/5) -(4/5)(-3/5) = 12/25 + 12/25 = 24/25
The desired sine is 24/25.
Seven units long. The distance between 2 sides, in this example is 6, and -1. The distance between 6 and -1 is 7, so when you add units, you get 7 units.
