Show that 1 2 2 a b c a b c a b c + = Hence express the following numbers in the form x + yn where x and y are rational numbers and n is an integer: (a) 1 7 5 + 2 (b) 2 3 2 9 7 2 + (c) 4 2 3 7 3 3 (d) 2 4 5 4 5 +