buatin jalannya yaa3a

jawab
a.

u20 = 42 --> a + 19 b = 42
u10 = 32--> a +9b = 32........(-)
10b = 10
b = 1

a +9b = 32
a + 9(1) = 32
a = 32 - 9
a = 23
U1 = a = 23


b)
u3 = 5 --> a + 2b = 5
u8 =-5 --> a + 7b = -5 .....(-)
-5b = 10
b = - 2

a + 2b = 5
a + 2(-2) = 5
a + 4 = 5
a = 1
u1 = a = 1