Ada yg tau gak ini pelajaran mtk​

Jawab:

1. Un = a + (n – 1) . b

U20 = 23 + (20 – 1) . 4

U20 = 23 + (19) . 4

U20 = 23 + (76)

U20 = 99

2. Un = a + (n – 1) . b

U15 = 95 + (15 – 1) . 4

U15 = 95 + (14) . 4

U15 = 95 + (56)

U15 = 151

4.

U8 = a + 7b = 33

U5 = a + 4b = 24

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3b = 9

b = 3

a + 4b = 24

a + 4(3) = 24

a + 12 = 24

a = 12

U30 = a + 24b

U30 = 12 + 24(3)

U30 = 12 + 72

U30 = 84

Maaf, cuman bantu sebisanya saja…

~ #Echayy