Question

could you help me with my math. 为什么用with?

Answer 1

动词help的用法是：

1. help sb (to) do sth  如：

   Many students help their mothers (to) do housework  at weekends.

2. help sb with sth  如：

   Many students help their mothers with housework  at weekends.
   

Answer 2

help sb. with sth. 帮助某人什么，固定搭配