Question

expand using identity (4x+5y)^3​

Answer 1

Answer:

Step-by-step explanation:

Answer 2

Answer:

64x^3+125y^3+240x^2y+300xy^2

Step-by-step explanation:

Given:

${(4x + 5y)}^{3}$

Using,

${(a + b)}^{3} = {a}^{3} + {b}^{3} + 3ab(a + b)$

Now,

${(4x + 5y)}^{3} \\ ={(4x)}^{3}+ {(5y)}^{3} \\ \: \: \: \: \: +3(4x)(5y)(4x+5y) \\ =64 {x}^{3}+125 {y}^{3} +60xy(4x + 5y) \\ = 64{x}^{3}+125{y}^{3}+240{x}^{2}y \\ +300x{y}^{2}$

Hence, the answer is

64x^3+125y^3+240x^2y+300xy^2.