I know! It's kind if annoying tbh...
A square with 1,536 soldiers are not possible, i.e. the square root of 1,536 is about 39.191, which means that 1,536 is not a square a number. In order for it to be a square number, we have to round up 39.191 (because it says "how many more soldiers") to 40 and 40×40=1,600 and 1,600-1,536, so we need 64 more soldiers.
The greatest 4 digit number is simple. If the square root of 10,000 is 100, than, one can assume that because 100-1=99, the resulting answer of 99×99 is less than 10,000, meaning that is is 4 digits. 99×99=9,801.
Let
be the dimensions of the rectangle. We know the equations for both area and perimeter:


So, we have the following system:

From the second equation, we can deduce

Plug this in the first equation to get

Refactor as

And solve with the usual quadratic formula to get

Both solutions are feasible, because they're both positive.
If we chose the positive solution, we have

If we choose the negative solution, we have

So, we're just swapping the role of
and
. The two dimensions of the rectangle are
and 
Answer:
where is the graph? please provide a graph.