The advancement of technology has always had an impact on our understanding of the world and played a role in renewing the definition of art. The ‘X’ and ‘Y’ in the exhibition title X+Y: Duo Solo Exhibition of Phoebe Hui and Tung Wing Hong – alluding to X and Y chromosomes, which determine sex differences – were metaphors for the different backgrounds of the two participating artists and their divergent views on technology. Featuring two large-scale participatory artworks which the artists created respectively with a variety of mediums and equipment as well as with the use of cutting-edge technologies, the exhibition explored how technology has influenced our perception of ourselves and our surroundings. ‘X’ and ‘Y’ are variables in algebra as well; at the exhibition, they also represented the unpredictable creativity of the artists. There was, however, another unknown, Z, which suggested audience’s participation in this interactive exhibition. The totality of the exhibition could be summed up in this equation: ‘X+Y=Z’.