Question

If (x + y) : (x – y) = 4 : 1, then (x² + y²) : (x² – y²) is ______.

Options

• 8 : 17

• 17 : 8

• 16 : 1

• 25 : 9

Answer 1

If (x + y) : (x – y) = 4 : 1, then (x² + y²) : (x² – y²) is 17 : 8.

Explanation:

Let x + y = 4k and x – y = k.

Then `x = (5k)/2` and `y = (3k)/2`; hence x² + y² : x² – y² = 17 : 8.