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23 votes
23 votes
Expand (2x – 3y)^38x3 - 27y38x3 - 36x2y + 54xy2 - 27y3ОАOB8x3 - 24x2y + 18xy2 - 27y38x3 + 36x²y - 54xy2 + 27y3D

Expand (2x – 3y)^38x3 - 27y38x3 - 36x2y + 54xy2 - 27y3ОАOB8x3 - 24x2y + 18xy2 - 27y-example-1
User Zahara
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1 Answer

11 votes
11 votes

\begin{gathered} (2x-3y)^3\text{ = }8x^3-36x^2y+54xy^2-27y^3 \\ \\ \text{option B} \end{gathered}

In this question, we want to expand the given expression. We do this by multiplying the terms with itself three times

we have;


\begin{gathered} (2x-3y)^{3\text{ }}\text{ = (2x-3y)(2x-3y)(2x-3y)} \\ \\ =\text{ (2x(2x-3y) - 3y(2x-3y))}(2x-3y) \\ \\ =(4x^2-6xy-6xy+9y^2)(2x-3y) \\ \\ =(4x^2-12xy+9y^2)(2x-3y) \\ \\ =2x(4x^2-12xy+9y^2)-3y(4x^2-12xy+9y^2) \\ \\ =8x^3-24x^2y+18xy^2-12x^2y+36xy^2-27y^3 \\ \\ =8x^3-24x^2y-12x^2y+18xy^2+36xy^2-27y^3 \\ \\ =8x^3-36x^2y+54xy^2-27y^3 \end{gathered}

User Wataru
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