Write an algebraic to model the phrase.

the base price of a car plus 7.5% tax represents the total cost of the car.

If n is the base price then the total cost is 1.075n  or 1.075n=total cost.

!00% of the price of the car + 7.5% tax = 107.5%  or 1.075 as a decimal.

So when you find 1.075 of the price (n) you are finding the total cost.

Notice how multiplying by the 1 in 1.075 included the cost of the car because 1 x anything is that thing.   1 x n = n