First, we can rewrite this expression as:
#(4p - 5q)(4p - 5q)(4p - 5q)#
Next, we can multiply each term within the left parenthesis by each term within the middle parenthesis:
#(color(red)(4p) - color(red)(5q))(color(blue)(4p) - color(blue)(5q))(4p - 5q)#
#((color(red)(4p) xx color(blue)(4p)) - (color(red)(4p) xx color(blue)(5q)) - (color(red)(5q) xx color(blue)(4p)) + (color(red)(5q) xx color(blue)(5q)))(4p - 5q)#
#(16p^2 - 20pq - 20pq + 25q^2)(4p - 5q)#
#(16p^2 - 40pq + 25q^2)(4p - 5q)#
Now, we can multiply each term in the parenthesis on the left by each term in the parenthesis on the right to complete the multiplication:
#(color(red)(16p^2) - color(red)(40pq) + color(red)(25q^2))(color(blue)(4p) - color(blue)(5q))#
#(color(red)(16p^2) xx color(blue)(4p)) - (color(red)(16p^2) xx color(blue)(5q)) - (color(red)(40pq) xx color(blue)(4p)) + (color(red)(40pq) xx color(blue)(5q)) + (color(red)(25q^2) xx color(blue)(4p)) - (color(red)(25q^2) xx color(blue)(5q))#
#64p^3 - 80p^2q - 160p^2q + 200pq^2 + 100pq^2 - 125q^3#
#64p^3 - 240p^2q + 300pq^2 - 125q^3#
