309 is the same as 93 subtracted from the quantity f times 123. The quantity f times 123: 123f Subtract 93: 123f - 93 The phrase is the same as means an equation, so we set 123f - 93 equal to 309 123f - 93 = 309 <-- This is our algebraic expression If you wish to solve for f, type this equation into the search engine, and we get f = 3.2683.