TRANSLATE('source', 'from', 'to') replaces each character in 'from' with corresponding character in 'to'. Here: '235' maps to 'xy' (2→x, 3→nothing, 5→y). So '123456789' becomes '1xy46789' - 2 becomes x, 3 is removed, 5 becomes y. The key is understanding that 3 maps to empty string.