nomor 10 dan 11 ya sama cara nya tolong

*Nmr 10*
Dik: a= 4; u2= 7; u3= 10; b= 3

U15= a + (n-1)b
= 4 + (15-1)3
= 4 + 14×3
= 4 + 42
= 46
[C]


*Nmr 11*
Dik: n= 12; a= 8; b= 2

U12= 8 + (12-1)2
= 8 + 11×2
= 8 + 22
= 30

Sn= n/2 (a+Un)
= 12/2 (8+30)
= 6 × 38
= 228
[C]