Given a and b are rational numbers. Find a and b if : (i) 3 − √5/3 + 2 √5 = −19/11 + a√5 (ii) √2 + √3/3√2 − 2√3 = a − b√6 (iii) 7 + √5/7 − √5 − 7 − √5/7 + √5 = a + 7/11b√5