The cost of laundering all of Leo’s trousers is 10 * 9 = <<10*9=90>>90 dollars
Since the total bill was 140 dollars, this means that all the shirts were cleaned for 140 - 90 = <<140-90=50>>50 dollars.
As each shirt is cleaned at 5 dollars, Sudsy Laundry therefore laundered a total of 50/5 = <<50/5=10>>10 shirts
The missing shirts are therefore 10 - 2 = <<10-2=8>>8 shirts
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