After the price of a drug increased by 30% in 2006, the price decreased by 70% to 30 yuan in 2007. How much is the price of this drug before the price increase in 2006? Formula or equation

After the price of a drug increased by 30% in 2006, the price decreased by 70% to 30 yuan in 2007. How much is the price of this drug before the price increase in 2006? Formula or equation

Let's assume that the price in 2006 is X
Then x (1 + 0.3) (1-0.7) = 30
X=76.92

After the price of a drug increased by 30% in 2001, it was reduced by 70% to a yuan in 2003. How much is the price of this drug increased in 2001?

You can use the hypothetical method
Suppose the original price is 100 yuan
30% price increase: 100 * (1 + 30%) = 130 yuan
70% reduction: 130 * (1-70%) = 39 yuan
The price in 2001 is a / 30%

In 2006, the price of a certain medicine increased by 30%; in 2007, the price decreased by 70% to a yuan. How much will it cost in 2006?

A÷（1-70%）÷[300+（1+30%）]