Question

Yg thu tolong di bantuin yahh??

Answer 1

16.  3^(x-2y) = 1/81
   3^(x-2y) = 3^-4
   x - 2y = -4
 2^(x-y) -16 = 0
2^(x-y) = 16
2^(x-y) = 2^4
x - y = 4

x - 2y = -4
x - y = 4
  - y = -8
  y = 8
x - y = 4
x - 8 = 4
x = 12
x+ y = 20  (B)