Question

Tolong jawab yaaa... Tapi Pake cara ok

Answer 1

No. 6
U3=a+2b=10
U7=a+6b=22

a+2b=10
a+6b=22

-4b=-12
b=3

a+2b=10
a+6=10
a=4

Sn=n/2(2a+(n-1)b)
S30=15(2(4)+29(3))
S30=15(8+87)
S30=15(95)
S30=1425 (B)

No. 7
7, 15, 23, 31, 39,...
a=U1=7
b=U2-U1=15-7=8

Un=a+(n-1)b
U50=7+49(8)
U50=7+392
U50=399 (B)