(1½ + 11½ + 111½ + 1111½) is equal to:

If x² + 1/x² = 51, then (x − 1/x) is equal to

√(2.25) + √(0.0064) + √(2.89) + 1 is equal to:

If 1² + 2² + 3² + ... + 10² = 385, then 3² + 6² + 9² + ... + 30² is equal to:

If 1² = 1, 11² = 121, then 111² = ?

If a/h + y/b = 1 and b/y + z/c = 1, then h/a + c/z will be equal to -