Answer:
Step-by-step explanation:
Its x= 30
2^3= 8
15-7= 8
4/2= 2
8 * 8 * 2
64 * 2
answer: 128
Forth term of the sequence is 61
Let's just go from a1 to a4:
a1 = 5
a2 = 2x5+3 = 13
a3 = 2x13+3 = 29
a4 = 2x29+3 = 61