Question

aio 6. In an arithmetic sequence, = 28 and ans = 223. what is the sum of the first loo terms? (5pts)

Answer 1

that Given 910 = 28 and 275 = 223 an = a + (n-1) ii a10 = 0,+(10-1)d 28 - 9, +9d u 075= 9,+(15-1)d 223 = 9,7740 2 Subtract from a +74d = 223 ait ad 28 6sd 195 a = 195 3 65 Substitute d in a, tad=28 9, + 913) = 28 a =28-27=1 i, a, = 1 ; d=3 Sum of first in terms Sn=1 (22+(n-1)d)

Sum of first 100 terms (201) + (100-1)3] S10o = loo 50 [2+99(3)] 50 [27297] 50 [299 Sioo = 14,950