It shows that it costs 16 1*2=322 yuan to buy 6 soccer balls and 4 basketball balls.
It costs 294 yuan to buy 6 footballs and 3 basketballs.
So the unit price of basketball
=322-294
=28 yuan
therefore
You have to pay for two basketballs.
28*2
=56 yuan
therefore
You have to pay for three footballs.
16 1-56
= 105 yuan
therefore
Unit price of football
= 105/3
=35 yuan
therefore
You need to pay 10 football and 5 basketballs.
35* 10+28*5
=350+ 140
=490 yuan