Your friend rents 10 chairs and 2 tables for $300. another friend rents 8 chairs and 4 tables for $360. you want to rent 12 chairs and 3 tables. how much do u expect to pay?

10c+2t=$300

20c+4t=$600

8c+4t=$360

Now you have both variables with the same number of tables so that you can effectively find out the cost of the chairs.

600-360=240

since 20-8 is 12,

12c=$240

1 chair costs 240:12 = $20

1 chair costs $20.

since 10c+2t=$300,

$200+2t=$300

and 2t costs $100.

hence 1 table costs $50.

if you want to rent 12 chairs and 3 tables,

12*20 is $240

100*3 is $300.

In total you need 300+240 = $540