A fashion store sets markup at 3/4 of its cost for the item. Find the cost of an item whose selling price is $42. Selling price is cost plus markup.
Let C be the original cost......and we know that....
1C + (3/4)C = 42 simplify
C(7/4) = 42 multiply both sides by (4/7)
C = 42(4/7) = (42/7)(4) = (6)(4) = $24 and this was the cost