Caranya Kak Bantu ( Boleh )

no.11
(-3)k+1 .7 .3pangkat-k
= -3k-3 .7.-3k
-3k÷3k = -3.7
-k = -21
k = 21
Jadi jawabannya D (21)
no.13
a.b.b = 20
a.b = 10
b = 10
a.b = 10
a.10= 10
a= 1

a-b/3 = 1-10/3
=9/3
=3

Jadi Jawabannya C(3)