Answer:
x=-2
Step-by-step explanation:
3x-1=8x+8+1
3x-1 = 8x+9
3x-1+1=8x+9+1
3x= 8x+10
3x-8x=8x+10-8x
-5x=10
-5x ÷-5
10 ÷-5
x=-2
3 slots
1st slot has 10 possible people
2nd slot has 9 possible people (1 less than previous)
3rd slot has 8 possible people
so there are 10*9*8 ways or 720 ways