tentukan suku suku yg diminta pada soal : a.U18 jika U1 =2 dan U10=38 b.U12 jika U3=7 dan U4+U7 =29

a. U1 = 2 = a
U10 = a + 9b =38
2 + 9b = 38
9b = 36
b = 4
maka, U18 = a + 17b = 2 + 17. 4 = 2 + 68 = 70

b. U3 = a +2b = 7
U4 + U7 = a +3b +a +6b = 2a + 9b =29

di eleminasi dan subtitusikan
a + 2b = 7 | x2 | 2a + 4b = 14
2a +9b = 29 | x1 | 2a + 9b = 29
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-5b = - 15
b = 3

a + 2b =7
a + 6 = 7
a = 1

U12 = a + 11b = 1 + 11 . 3 = 34