Question

If 2^2x+y = 4^x-y-3 = 1, then (x, y) is
a. (-1, -2)
b. (-1, 2)
c. (1, 2)
d. (1, -2)

{ALIGARH MUSLIM UNIVERSITY +2 ENTRANCE TEST 2013-14}

Answer 1

2^2x+y=1 and 4^x-y-3=1
2^2x+y=2^0 4^x-y-3=4^0
2x+y=0 x-y-3=0
x=-y/2 -y/2-y=3
(-y-2y)/2=3
-3y=6
y=-2
and x=1

Answer 2

HELLO DEAR,



- - - - - - - - - - - 2^(2x+y)=1--------

2^(2X +Y) =2^0

-----------2X + Y = 0------(1)


—-------------4^(x-y-3)=4^0----------

X-y-3=0------------(2)

From (1) and (2)

2x+y=0
X-y=3
-------------------
3x=3
=> x=1


Now put the value of x in (1)


We get,

2*1+ y =0

=>y = - 2


I HOPE ITS HELP YOU DEAR,
THANKS