Question

Find the first, fourth and eighth terms of the sequence. A(n)=-5•2^x-1 help me please !

Answer 1

Replace the x by 1, 4 and 8 and perform the calculation:-

first term = A(1)  = 5 * 2^(1-1) =  5* 2^0 = 5*1 = 5 answer

4th term = 5 * 2^(4-1) = 5 * 2*3  = 40 answer

8th term = 5 * 2^(8-1) = 5 * 2^7 = 640  answer