Penjelasan dengan langkah-langkah:

Rumus suku ke-n:

Un = a + (n - 1) b

a adalah suku ke-1 / U1

b adalah beda/selisih tiap sukunya

a. 0, 2, 4, 6

U1 / a = 0

U2 = 2

U3 = 4

U4 = 6

b = U2 - U1 = 2 - 0 = 2

U10 = 0 + (10 - 1) 2 = 9.2 = 18

U25 = 0 + (25 - 1) 2 = 24.2 = 48

b. 1, 4, 7, 10, 13

U1 / a = 1

U2 = 4

b = 4 - 1 = 3

U10 = 1 + 9.3 = 1 + 27 = 28

U25 = 1 + 24.3 = 1 + 72 = 73

c. 10, 7, 4, 1

U1 / a = 10

b = 7 - 10 = -3

U10 = 10 + 9(-3) = 10 - 27 = -3

U25 = 10 + 24(-3) = 10 - 72 = -62

d. 1/3, 5/6, 8/6, 11/6

U1 / a = 1/3 = 2/6

U2 = 5/6

b = 5/6 - 2/6 = 3/6

U10 = 2/6 + 9.3/6 = 2/6 + 27/6 = 29/6

U25 = 2/6 + 24.3/6 = 2/6 + 72/6 = 78/6 = 13

Semoga kamu jadi ngerti ya!