Question 136863
Let x=number of seats in the orchestra section
And y=number of seats in the balcony section

Now we are told the following:

x+y=360-----------------------------------------------eq1
and ($ understood)
45x+35y=15,150-----------------------------------------eq2
eq2 reduces to (divide each term by 5):
9x+7y=3030-------------------------------------------------eq2a
from eq1, we see that x=360-y, substitute this into eq2a:

9(360-y)+7y=3030 get rid of parens
3240-9y+7y=3030  subtract 3240 from each side

3240-3240-9y+7y=3030-3240 collect like terms

-2y=-210 divide both sides by -2
y=105------------------------------------number of seats in the Balcony sect.

Substitute y=105 into eq1:

x+105=360  subtract 105 from each side

x=255------------------------number of orchestra seats

CK

105+255=360
360=360

and
45*255+35*105=15,150
11,475+3,675=15,150

15,150=15,150

Hope this helps----ptaylor