Question

An item with an original price of d dollars has its price increased by x percent in April and then decreased by x percent in May. The resulting price is 4 percent less than the original price. What is the value of x?

Answer 1

So the final price would be:
d(100+x)(100-x) / 100²
= d(100² - x²) / 100²
= d(1 - (x/100)²)