To exclusively rent a videoke room, a certain number of people will have to pay equal amounts to a total of 720 php. If there were 3 persons less, each person would then have to contribute 40 php more. How many people were there originally?

Question

ahsome · Answer

Assuming php is a type of currency and 720 is total cost:
You have two unknowns, the number of students and the cost per student:
Let x be the number of students and y be the cost per student
$$xy=720$$
$$x-3=y+40$$
Simplify 2nd Question
$$x=y+43$$
Rearrange the first equation
$$x=720/y$$
Now you know this:
$$720/y=y+43$$
Solve from there. If you still need further help, just tell me @raechelvictoria

ahsome · Answer

That will give you the value of y. Sub that into x to get the number of students

ahsome · Answer

(Need someone to clarify) @iambatman @Kainui