i would just make this into an equation!!
t for the number of turkey sandwiches
s for the number of steak sandwiches
it's 4 dollars for every turkey sandwich and 6 for every steak sandwich, so:
4t + 6t = 4524
you can call this your "profit" equation. it just tells you how much money they made. however many sandwiches they sold at those rates gave them the outcome of 4524
then you need a second equation, to account for the number of sandwiches, and instead of worrying about profit you need to focus on the number of sandwiches sold (which is why they gave you the number 925)
t + s = 925
the number of turkey sandwiches plus the number of steak sandwiches adds up to a total of 925 sandwiches.
so you have two equations:
4t + 6s = 4524
t + s = 925
to figure out the number of turkey sandwiches sold, you want to solve for the variable t. this can be done a few ways with your two equations, but the easiest to follow will probably be substitution in this case.
first, isolate your variable t in one of the equations. it'll be easier with the second one.
t = 925 - s
then you plug that into your first equation:
4(925 - s) + 6s = 4524
then solve it like normal.
4(925 - s) + 6s = 4524
3700 - 4s + 6s = 4524
3700 + 2s = 4524
2s = 824
s = 412
so now you know your s variable. plug that back into the following equation, and you have the number of turkey sandwiches sold:
t = 925 - s
t = 925 - (412)
t = 513
513 turkey sandwiches were sold