diketahui u3 =6 dan jumlah u2+u5=10, tentukan suku 10 barisan tersebut

langsung aja y

U3 = a + 2b = 6

U2+U5 = 10
a + b + a + 4b = 10
2a + 5b = 10

a + 2b = 6 (×2)
2a + 5b = 10 (×1)

2a + 4b = 12
2a + 5b = 10
__________-
-b = 2
b = -2

a + 2b = 6
a = 6 - 2(-2)
a = 6 + 4
a = 10

U10 = a + 9b
U10 = 10 + 9(-2)
U10 = 10 - 18
U10 = -8

semoga berguna +_+