Hi David,

I would first write a mathematical sentence (equation) that describes the statement

"120 minus a 12% discount is 105.6."

A 12% discount in $120 is 12% of 120 and 12% of 120 is ¹²/₁₀₀ 120 = 0.12 120. Thus the equation is

120 - 0.12 120 = 105.6

In the situation you describe you know the discount rate is 12% and you know the discounted price is $105.60, but you don't know the original price of $120. You call the original price $x so in this case the equation is

x - 0.12 x = 105.6

Thus

0.88 x = 105.6

Divide both sides by 0.88 to get

x = ^105.6/_0.88 = 120

Penny

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