**Answer:**

Number of basketball = 9

Number of football = 15

**Step-by-step explanation:**

let number of basketball = x

let number of football = y

Given that cost of 1 basketball = 22

Then cost of x basketball = 22x

Given that cost of 1 football = 30

Then cost of x football = 30y

Then total expense = 22x+30y

Given total expense is $648 so we can set both equal to each other and get:

22x+30y=648...(i)

Given that they bought 6 more footballs than basketballs

so we get:

y=6+x...(ii)

Now plug (ii) into (i)

22x+30y=648

22x+30(6+x)=648

22x+180+30x=648

52x+180=648

52x=648-180

52x=468

x=9

plug x=9 into (ii)

y=6+x=6+9=15

Hence final answer is :

Number of basketball = 9

Number of football = 15