Let x represent the cost of a dozen roses. 5 dozen roses can be purchased for $62.50 . Consider the following equation. 5x = $62.50. Here the product and factor are known, thus divide by the factor on both sides of the equation.
5x $62.50
-- = --
5 $12.50
Now to find out the cost of 8 dozens multiply the value of x by 8.
If a car depreciates by 7% each year, this means that 7% of its value that year is subtracted from its previous value. In other words, you can multiply its value by (1-0.07)=0.93.