prep 数学请教

pengxiaomi

请NN帮忙解答一下，谢谢

pengxiaomi

the rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concerntration of chemical B present. If the concerntration of chemical B is increased by 100percent, which of the following is closest to the percent change in the concentration of Chemical A required to keep the reaction rate unchanged.

1) 100%decrease

2) 50% decrease

3)40% decrease

4)40% increase

5)50% increase