7m(4m^2·p)^2=7m*4^2*(m^2)^2*p^2
=7m*4^2*m^4*p^2
=7*16m*m^4*p^2
=112m^5*p^2
所以7m(4m^2·p)^2÷7m^2=112m^5*p^2÷7m^2=16m^3p^2