18(2a-b)-4(2a-b)-13
=36a-18b-8a+4b-13
Rearrange
=36a-8a-18b+4b-13
=28a-14b-13
47.50 = 8.50x + 5
42.50 = 8.50x
x = 5
Wylie can rent for 5 hours.
∑ ( from n = 1 to n =5 ) 3 · ( -2 ) ^( n -1 )
a 1 = 3 · ( -2 ) ^0 = 3
a 2 = 3 · ( - 2 ) = - 6
a 3 = 3 · 4 = 12
a 4 = 3 · ( - 8 ) = - 24
a 5 = 3 · 16 = 48
3 - 6 + 12 - 24 + 48 = 33
Answer: C ) 33
