Question

2 Write the following cube in expanded form : (2x - 3y")
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Answer 1

$(2x-3y)^3$

$\sf\red{Identity\:used:} (a-b)^3=a^3-b^3-3a^2b+3ab^2$

$\\ \implies (2x-3y)^3 \\ \\ \implies (2x)^3 - (3y)^3 - 3(2x)^2(3y) + 3(2x)(3x)^2 \\ \\ \implies (8x)^3 - (27y)^3 - 36x^2y + 54xy^2 \\ \\ \implies 8x^3 -9y (3y^2 - 4x^2 + 6xy)$