Let
x -----> number of play student tickets sold
y ----> number of general admission tickets sold
we have that
x+y=177 ------> x=177-y -----> equation A
7x+9y=1365 -----> equation B
solve the system
substitute equation A in equation B
7(177-y)+9y=1365
solve for y
1239-7y+9y=1365
2y=1365-1239
2y=126
y=63
Find the value of x
x=177-63
x=114
therefore