Answer:
3960 feet
Step-by-step explanation:
-2x • 3x = -6x2 (the 2 is an exponent)
4y • -7y = -28y2 (the 2 is an exponent)
-2x • -7y = 14xy
4y • 3x = 12xy
14xy + 12xy = 26xy
—> -6x2(expo) - 28y2(expo) + 26xy
Check the answer again just to be sure, it’s been a while since I’ve had algebra!
Answer:
C. √2 - 1
Step-by-step explanation:
If we draw a square from the center of the large circle to the center of one of the small circles, we can see that the sides of the square are equal to the radius of the small circle (see attached diagram)
Let r = the radius of the small circle
Using Pythagoras' Theorem 
(where a and b are the legs, and c is the hypotenuse, of a right triangle)
to find the diagonal of the square:



So the diagonal of the square = 
We are told that the radius of the large circle is 1:
⇒ Diagonal of square + r = 1





Using the quadratic formula to calculate r:




As distance is positive,
only
The direct variation that can be established using the given parameters is that, the time it takes between seeing the lightning and hearing the thunder is directly related to the speed.
However, it can also be established that the time described above is inversely proportional to the distance. This can be written as,
t = k/d
We substitute the given expression for each of the known terms. t is time, s, and d is distance, 3s.
s = k/3s
The k written in the equation is the constant of proportionality.
Elio is right in assuming the relationship between the height and the hours it burns is proportional.
Find the unit rate
14 ÷ 8 = 1.75 cm/h
Divide
21 ÷ 1.75 = 12
You can set this up as an algebraic equation to check the answer.
If the candle is 21 cm tall, it will burn for 12 hours.
Hope this helped you! :)