yang nomer 11 tolong yg bisa nggih

6a + b = 23 - 2a + b = 7 sehingga a = 4
2 * 4 + b = 7 sehingga b = -1
Un = 4n - 1
U40 = 159

11. U2 = 7 ; U6 = 23
= a + (6-1) b = 23 a + b = 7
a + (2-1) b = 7 = a + 4 = 7 --> a = 3
———————— -
4b = 16
b = 4

U40 = 3 + (40 - 1) × 4 = 159 (B)