Answer:
a) yx=63
b) y=3
Step-by-step explanation:
a)
yx=k (inverse formula)
7(9)=k
63=k
b)
y(21)=63
y=63/21
y=3
Answer:

Step-by-step explanation:
This is the distance formula for cartesian coordinate systems, or your typical xy graph. If given two points to find the distance between, you can assign '1' or '2' to the points, i.e. (1,1) and (2,2) could be: (1,1) is (x1,y1) and (2,2) is (x2,y2). It doesn't matter which point is 1 or 2. If we were to use those example points in this formula, we would have:

We can simplify and come up with:
=
We must remember that square roots can be positive OR negative, HOWEVER, because you are looking for a distance it must be positive
.
Hope this helped!
Answer:
893.3816
Step-by-step explanation:
pretty sure your converting gallons into pounds and if that's the case 4 gallons is 33.3816 lbs so I added 860 + 33.38.16 then I got 893.3816
N is equal to 2 in the equasion
Answer:
a = 36 and a = 27
Step-by-step explanation:
The geometric mean of two numbers is the square root of the product of the two numbers.
Say for example we have the numbers x and y, the geometric mean z is mathematically;
z = √xy
For the first question, our z is 12, x and y are 4 and a respectively.
12 = √4a
square both sides
144 = 4a
a = 144/4
a = 36
For the second question
z is 9, x and y are 3 and a respectively
9 = √3a
square both sides
81 = 3a
a = 81/3
a = 27