I hope this helps you
4/6=4.6/6.6=24/36
4/9=4.4/4.9=16/36
24/36+16/36
24+16/36
40/36
4.10/4.9
10/9
Lagrange multipliers:







(if

)

(if

)

(if

)
In the first octant, we assume

, so we can ignore the caveats above. Now,

so that the only critical point in the region of interest is (1, 2, 2), for which we get a maximum value of

.
We also need to check the boundary of the region, i.e. the intersection of

with the three coordinate axes. But in each case, we would end up setting at least one of the variables to 0, which would force

, so the point we found is the only extremum.
The answer for how many yards are in 1 mile 60 feet is 1780
If C stands for cups, solve for C
48 - 2c = 0
l
subtract 48 from each side.
l
2c=-48
l
divide 48 by 2 ---> 24.