we need y-x. If we have the value of x, we'll have the answer. We know thatgrandh01 wrote:If y = 2^x+1, what is the value of y - x?
(1) 2^2x+2 = 64
(2) y = 2^2x -1
y= 2^x+1
Lets look at the statements:
(1) 2^(2x+2) = 64= 2^6 => x = 2.
We have found a unique value of x from this equation by comparing bases. Sufficient.
(2) y = 2^(2x -1)
Comparin this to given value of y:
2^(x + 1) = 2^(2x-1)
x+ 1 = 2x-1 => x =2. Sufficient again.
D is correct.
