Question 9443
Let x = price of TV on the left side (least expensive)
x+20 = 2nd TV
x+40 = 3rd TV
x+60 = 4th TV
x+80 = 5th TV
x+100 = 6th TV
x+ 120 = 7th TV 
and so onm notice the pattern is x + 20(n-1)

x + 12*20 = price of 13th TV on the right side (most expensive)
x + 240 = 13th TV


Price of the TV on the right = Price of 2nd + 7th TV
x+240 = x+20 + x+120
x+240 = 2x + 140


Subtract x from both sides:
x+240 - x = 2x -x + 140
240 = x + 140
100 = x


Least expensive TV = $100.


Check:  Most expensive TV = $100 + 12*20 = $340
2nd TV = $120
7th TV = $220


GOOD PROBLEM!!  


R^2 at SCC