Identify series type: Identify the type of series.The series is of the form −4(−2)k, which is a geometric series because each term is obtained by multiplying the previous term by a common ratio.
Determine first term: Determine the first term of the series.The first term is obtained when k=0, which gives us −4(−2)0=−4(1)=−4.
Determine common ratio: Determine the common ratio of the series.The common ratio is −2, as each term is multiplied by −2 to get the next term.
Use formula for sum: Use the formula for the sum of a finite geometric series.The sum S of a geometric series with first term a, common ratio r, and n terms is given by S=(1−r)a(1−rn), provided that r=1.
Apply formula to series: Apply the formula to the given series.Here, a=−4, r=−2, and n=20 (since we are summing from k=0 to k=19, which gives us 20 terms).S=−4(1−(−2)20)/(1−(−2))
Calculate sum: Calculate the sum.S=−4(1−220)/(1+2)S=−4(1−1048576)/3S=−4(−1048575)/3S=4×1048575/3S=4194300/3