**Given:**

The sequence is
an=(−1)n−15n
. (1)

**Calculation:**

Obtain the first term of the sequence.

Substitute 1 for *n* in equation (1).

a1=(−1)1−151 =(−1)05 =15

Thus, the first term of the sequence is
a1=15_
.

Obtain the second term of the sequence.

Substitute 2 for *n* in equation (1).

a2=(−1)2−152 =(−1)125 =−125

Thus, the second term of the sequence is
a2=−125_
.

Obtain the third term of the sequence.

Substitute 3 for *n* in equation (1).

a3=(−1)3−153 =(−1)2125 =1125

Thus, the third term of the sequence is
a3=1125_
.

Obtain the fourth term of the sequence.

Substitute 4 for *n* in equation (1).

a4=(−1)4−154 =(−1)3625 =−1625

Thus, the fourth term of the sequence is
a4=−1625_
.

Obtain the fifth term of the sequence.

Substitute 5 for *n* in equation (1).

a5=(−1)5−155 =(−1)43125 =13125

Thus, the fifth term of the sequence is
a5=13125_
.

Therefore, the first five terms of the sequence are
15,−125,1125,−1625,13125
.