Verified Answer :

easey, just multiply everybody and add the exponents for like terms remember
(a^m)(a^n)=a^(m+n)
also
(ab)c=a(bc)
so

-4x³y²(7xy⁴)=
-4x³y²7xy⁴=
-4
7x³xy⁴y²=
-28x⁴y⁶
-28x⁴y⁶