Find the roots of the following quadratic equations by factorisation: (i) x^2 - 3x - 10 = 0 (ii) 2x^2 + x - 6 = 0 (iii) sqrt(2)x^2 + 7 + 5sqrt(2) = 0 (iv) 2x^2 - 1/8 = 0 (v) 100x^2 - 20x + 1 = 0