When x = 3 z = 57 57/3 = 19
19*8 = 152
So when X is equal to 8, Z is equal to 152.
The slope is 1, because the slope form is:

Where the m is the slope. Here, m=1.
In order to solve this we need to make on part of both statements equal.
Since 12 is divisible by 6 lets do that.
Multiply everything in the second package by 2.
It then becomes 6 pairs for $12.
So now have have 6 or 8 pairs for $12.
You are getting a different amount for the same price therefore they are not proportional.
The moon is roughly a sphere, with an average radius of 1,738 kilometers.
The area of a sphere is 4 pi R² .
Area of the moon = (4 pi) (1,738 km)² =
(12.566) (3,020,644 km²) = 3.796 x 10⁷ km²