4的x次方+4的-x次方-4乘以(2的x次方+2的-x次方)-3=0
2的2x次方+2的-2x次方-4乘以(2的x次方+2的-x次方)-3=0
2的x次方+2的-x次方=y
y²-2-4y=3
(y-5)(y+1) y=5 y=-1(舍去)
2的x次方+2的-x次方=5
2^x+1/2^x=5
4的x次方+4的-x次方-4乘以(2的x次方+2的-x次方)-3=0
2的2x次方+2的-2x次方-4乘以(2的x次方+2的-x次方)-3=0
2的x次方+2的-x次方=y
y²-2-4y=3
(y-5)(y+1) y=5 y=-1(舍去)
2的x次方+2的-x次方=5
2^x+1/2^x=5