Hello! And thank you for your question!
First Distribute:
25x^2(5x−4y)+20xy(5x−4y)+16y^2(5x−4y)
Then distribute again:
125x^3−100x^2y+20xy(5x−4y)+16y^2(5x−4y)
Distrubute another time:
125x^3−100x^2y+100x^2y−80xy^2+16y^2(5x−4y)
And one last time distrubute:
125x^3−100x^2y+100x^2y−80xy^2+80y^2x−64y3
After distributing Simplify:
125x^3−80xy^2+80y^2x−64y3
Combine like terms:
125x^3+(−80xy^2+80xy^2)−64y3
Lastly simplify once more:
125x^3 - 64y^2
Final Answer:
125x^3 - 64y^2
