bantu jawab kak.. please 11-15 kak

11. Un= 2n^2 - 5
U4= 2.4^2-5
= 2.16-5 = 32-5 = 27
U5= 2.5^2-5
= 2.25-5 = 50-5 = 45
U4+U5 = 27+45=72(c)

12. Un= 2n^2 - n+5
U10= 2.10^2 - 10+5
= 2.100-10+5
= 190+5 = 250(c)

13. Un= 3.2^n-1 (c)
U2= 3.2^2-1
= 3.2^1
= 6
U3= 3.2^3-1
= 3.2^2
= 3.4 = 12
U4= 3.2^4-1
= 3.2^3
= 3.8
= 24

14. Un= 3n+2 (d)
U2 = 3.2+2
= 6+2=8

15. Un = 2n/n+1
U2 = 2.2/2+1 = 4/3
U3 = 2.3/3+1=6/4
U1 = 2.4/4+1=8/5
jawabannya yang B