问题 填空题 已知-x2myn+6与58x3n-1y2m+1是同类项,则m+n=______. 答案 ∵-x2myn+6与58x3n-1y2m+1是同类项,∴2m=3n-1n+5=2m+1,解得m=4n=3,∴m+n=4+3=7.故答案为7.