Gary and michelle are taking lunch orders for their office training session. a turkey club sandwich cost $3.75 and a roast beef sandwich costs $3.50. they collected $36.25 from the group of 10 people. how many people ordered turkey ?

3.75x + 3.50y = 36.25     where x and y  are the number of people to order turkey and beef respectively.
also we x + y = 10

so we have to solve this system of 2 equations

from the second equation y = 10 -x so substituting in first equn.:-

3.75x + 3.50(10-x) = 36.25
0.25x = 36.25 - 35 = 1.25
x = 1.25 / 0.25 = 5

so 5 people ordered turkey