代数式:4+5y,7,m,立方根号mn,1/y^2+1/x^2,-3a^2b,x^2-xy中,

问题描述:

代数式:4+5y,7,m,立方根号mn,1/y^2+1/x^2,-3a^2b,x^2-xy中,
属于整式的有:

7,m,3a^2b