Answer:
1079
Step-by-step explanation:
Hello,
18-5 = 13
31-18=13
44-31=13
161=5+13*12
So we need to compute
[tex]\displaystyle \sum_{k=0}^{k=12} \ {(5+13k)}\\\\=\sum_{k=0}^{k=12} \ {(5)} + 13\sum_{k=1}^{k=12} \ {(k)}\\\\=13*5+13*\dfrac{12*13}{2}\\\\=65+13*13*6\\\\=65+1014\\\\=1079[/tex]
Thanks