There are 2 ways you can write this.
You can either do /1 or /100

The most used is
The answer is 10 ft. make a triangle 6ft tall, 8ft long (90 degrees to the other line) and draw a line to complete the triangle. This is a type of 3,4,5 triangle, a 6,8,10. The other way to do it is sqrt(6^2+8^2) = sqrt(36+64) = sqrt (100) = 10.
M / k = x.....multiply both sides by k. eliminating the k on the left side
m = xk <==
To answer this, let the 3 sides of the regular sized rectangular box be x, y, and z.
When we double all the sides, the new sides have lengths 2x, 2y, and 2z, respectively.
Since the regular box (with dimensions x,y, and z) have 750 toothpicks, we can write

Similarly we can write for the jumbo box as,

which is equal to 
So this is 8 times the original of
. Hence the jumbo box will have 8 times 750 number of toothpicks.
ANSWER:
toothpicks
In order to be perpendicular, you must have a slope that is the opposite reciprocal, so the slope should by -3/4. So the equation could be y = -3/4x with any other number at the end.