If y/x = 2 − x/y, then the value of (x³ + xy²)/(x³ + y³) is equal to

If x + (1/x) = 3, then the value of x³ + (1/x³) is :

If (a² − 1)/a = 2, then the value of (a⁶ − 1)/a³ is:

If x + (1/y) = 1 and y + (1/z) = 1, then the value of z + (1/x) is

If 2^(x−1) + 2^(x+1) = 1280, then the value of x²+9x is

If x + y = 7 and 2x − y = 8, then y − x is equal to