Question

Diketahui barisan bilangan
-23,-17,-11,-5
Nilai U20 + U30 =

Answer 1

U20= a+19b
     = -23+19(-6)
     = -23+ -114
     = -137

u30= a+ 29b
     =-23+ 29(-6)
     = -23+ -174
     = -197

u20+u30= -137+ -197
            =  -334

Answer 2

U20 = -23 + 19 x 6
U20 = -23 + 104
U20 = 81

U30 = -23 + 29 x 6
U30 = -23 + 174
U30 = 151

U20 + U30 = 81 + 151
U20 + U30 = 232