问题

>> (ax^5+bx^4)(px^4+qx^3)
in> (ax^5+bx^4)*(px^4+qx^3)

out> a*a*a*a*a*p*p*p*px^9+(a*a*a*a*a*q*q*q+b*b*b*b*p*p*p*p)x^8+b*b*b*b*q*q*qx^7
------------------------

>> (a(x^5)+b(x^4))(p(x^4)+q(x^3))
in> (a(x^5)+b(x^4))*(p(x^4)+q(x^3))

out> x^7+qx^4
------------------------

>> (a*(x^5)+b*(x^4))(p*(x^4)+q*(x^3))
in> (a*(x^5)+b*(x^4))*(p*(x^4)+q*(x^3))

out> a*px^9+(a*q+b*p)x^8+b*qx^7
------------------------