Question 934435
1) -48 = 2x - 54
add 54 to both sides of =
2x = 6
x = 3
2) f(1) = 8
f(r) = f(r - 1) + 3 
row 1 has 8 seats
row 2 has f(1) +3 = 11 seats
row 3 has f(2) +3 = 14 seats
row 4 has f(3) +3 = 17 seats
3) first five terms are 6, 12, 24, 48, 96
this is a geometric sequence with a = 6 and r = 2, then we have
Xn = a*r^(n-1), where n is the nth term, therefore
Xn = 6*2^(n-1)