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put this solution on YOUR website!let x= the number of tv advertisements and y = the number of radio advertisements.
x+y=220 .........................1
sincew we know that the tv ads cost $500 and the radio ads $100 the total costs will be given by
500x+100y=30000..................2
we multiply the first equation by 100 and we have
100x+100y=22000..................3
equation 2 - 3
(500x-100x)+(100y-100y)=30000-22000
400x=8000
x=20
x+y=220
20+y=220
y=200
20 tv ads and 200 radio