If a^b = c^d, then log a / log c is

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

If 2^(2x−1) + 4^x = 2^(x−1/2) + 2^(x+1/2), then the ratio (1−x)/(1+x) is

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

If x is the largest and y is the lowest among ∜6, √2 and ∛4, then (x³+y²)/(x³−y²) is

If a, b, c, d, e and f satisfy 2a = 3b = 6c = 9d = 12e = 18f, then what is the value of (a + b)/(c + d + e + f)?