Question 252127
 2^x.4^y = 16 

so  2^x.2^2y = 2^4 
=>  2^(x+2y) = 2^4
=>  x+2y=4  -------------- 1

4^3x-2.(1/2)^y = 128
=> 2^(6x-4).2^(-y) = 2^7
=> 6x-4-y = 7
=> 6x-y=11  -------------- 2

solving equations 1 and 2 (multiply eq. 2 by 2 and add eq.1 )

x=2
y=1