Personally, I think it's math. Because mathematics is the father of science, learning mathematics well shows that you have the ability to learn science. This is a great help to you and society. Although English is also very important, it is said that most books in the world are written in English. English is a carrier. But if you are good at math, I think it doesn't matter if this carrier is not so good.
So, if you can really learn math well, its benefits will be English!