Length= y in.
Width= (y-6) in.
Perimeter = 2(L*W)
Perimeter=2L+2W
68in.=2(y)+2(y-6)
68=2y+2y-12
68=4y-12
68+12=4y
4y=80
y=20
Length= 20 inches, width =14 inches
If you do this with a complex set of fractions and let
K = G Me m_space be the same in both parts, there should be some cancellation.
W_earth = 180 lbs
W_earth = K /3900 miles^2
W_space =K /(3900 + 850)^2
180 / W_space = k/3900^2
x = k / (4750)^2
The ks cancel out.
You are left with 180/x = 4750^2 / 3900^2 Now cross multiply
180 * 3900^2 = 4750^2 = x
180 * 3900^2 / 4750^2 = x
180 * 0.67413 = x
x = 121 pounds. Weight is a force, but because all the units on one side are equivalent to the units on the other, the conversions become part of k. Normally you would have to do the conversions, but not in this particular case.
First graph your x and y intercept then pick any two points on the line.

that's the equation used to find your slope
Example:
(4,2) (8,6) let's say those are the points you pick from the line
so then you subtract 6-2=4 (6 is your y2 and 2 is your y1)
then subtracts 8-4=4 (8is your x2 and 4 is your x1)
then your left with

if you can reduce the reduce in this case you can which leaves you with

and that's how you find the slope
7 times 10 is 70, so in total the friends got that amount, but we aren’t done, because we still need to add the roll that he kept for himself, so it’s 71. Notice that it didn’t say he left a whole bag for himself, just one roll.