4xy (x cubed + 5xy - 7y squared)

Step-by-step explanation:

4xy (x^3+5xy-7y)

=4xy (x^3) + 4xy (5xy) - 4xy (7y)

=4x^4 y + 20x^2 y^2 - 28xy^2

4x^4y + 20x^2y^2 - 28x^3y

Step-by-step explanation:

4xy (x^3 + 5xy - 7x^2)

= 4xyx^3 + 4xy * 5xy - 4xy * 7x^2

= 4x^2y + 4xy * 5xy - 4xy * 7x^2

= 4x^4y + 20x^2y^2 - 4xy * 7x^2

= 4x^4y + 20x^2y^2 - 28x^3y