Question

3^(x-y) =27. 3^(x+y) =243 then x is?

Answer 1

Answer:4

Step-by-step explanation: Given :

3^(x-y) = 27 -----equation(1)

and 3^(x+y) = 243 -------equation (2)

To find : x

We know that 27 = 3 X 3 X 3

27 = 3^(3)

On comparing this with equation (1), we get,

3^(x-y) = 3^(3)

Therefore, x-y = 3 --------equation (3)

Similarly, we know, 243 = 3 X 3 X 3 X 3 X 3

243 = 3^(5)

On comparing this with equation (2), we get,

3^(x+y) = 3^(5)

Therefore, x+y = 5 --------equation (4)

Now, to find x, add equation (3) and equation (4),

(x-y) + (x+y) = 3 + 5

2x = 8

x = 4 --------------- Answer