18.Select the sum of the series. ₁⁶k²

39.The fundraising team starts with $170 in the bank. Each magazine that the team sells adds $8 to the savings. Put the terms in a formula similar to this scenario?

a1 = (?)

an = an-1 + (?)

17.What are the first five terms in the geometric sequencea_n= 5^{n - 1}, starting with n=1

21. What is the formula that represents a circle with a center of (-2, 1) and a radius of 5.

28. What is the equivalent expression to 4log (x+1) + log(x)

44.Simplify the following combination:C₈³