#### Explanation:

I'm going to work this two ways - first step by step, then all together.

Step by step:

We have a car with a value of $12,000. The dealership first raises the price by 15%: $12 , 000 \times 0.15 = 1800$- so the price increase is$1800 and the car is now on sale for:

$12,000 +$1800 = $13,800 And then the dealership announces a 15% off sale. What's the price of the car now? $13 , 800 \times 0.15 = 2070$- this is the price reduction, and so the final price of the car is: $13 , 800 - 2070 = 11 , 730$And so the "sale" isn't much of one at all - buyers only save $12000-$11730=$270

And now, all at once (I'll build the equation step by step):

We have the Old Price of the car (I'll call that $O P$) and the New Price of the car (I'll call that $N P$):

$O P = N P$

and we know that the Old Price is 12,000:

$12000 = N P$

Now what do we do to the Old Price? First we increase it by 15%:

$12000 \left(1 + 0.15\right) = N P$

and then we reduce the whole thing by 15%:

$\left(12000 \left(1 + 0.15\right)\right) \left(1 - 0.15\right) = N P$

and now we can solve:

$\left(12000 \left(1.15\right)\right) \left(0.85\right) = N P$

$\left(13800\right) \left(0.85\right) = N P$

$11730 = N P$