Question

Soal deret aritmetika tolongin aku ya guys​

Answer 1

Jawaban:

u3 = 30 <=> 30 = a + 2b

u6 = 51 <=> 51 = a + 5b

a + 5b = 51

a + 2b = 30

--------------- -

3b = 21

b = 7

diketahui beda = 7

suku pertama ??

30 = a + 2b

30 = a + 14

a = 30 - 14

a = 16

u15 = a + 14b

u15 = 16 + 14(7)

u15 = 114

\begin{gathered}s15 = \frac{15}{2} ( 16 + 114 ) \\ s15 = \frac{(15)(130)}{(2)} = 975\end{gathered}s15=215(16+114)s15=(2)(15)(130)=975

Penjelasan dengan langkah-langkah:

semoga mebantu