2x.7x(-4+9)=7 and (-1+9)4=9-7. The best set of answers came from Mike Shepherd of London SE21.
Now, naturally enough, we want to know which dates in May cannot turn into valid sums. Note a slight change in the rules: this time we allow only +, - , , x, = and as many brackets as you want. (Last time we allowed power-raising exponents too.)
A prize of the Chambers 21st Century Dictionary will be awarded to the sender of the best set of answers. Entries by 6 May to: Perplexity, The Independent,
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