hasana76
U2= 19 U5 = 31 dieliminasi U2 = a + b = 19 U5 = a + 4b = 31 --------------- (-) -3b= -12 b = 4 di subsikan a + b =19 a + 4 = 19 a = 15 jumlah 24 suku pertama n/2 (2a + (n-1)b 24/2 ( 2.15 + (24-1)4 12(30+(23.4) 12(30+92) 12(122) =1464. Semoga membantu