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Factorise 27x³ + 64y³.

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Factorise $27x^3 + 64y^3$ .

Need a reminder? The key ideaShow

$(x \pm y)^2 = x^2 \pm 2xy + y^2$ , $x^2 - y^2 = (x + y)(x - y)$ , $(x \pm y)^3 = x^3 \pm y^3 \pm 3xy(x \pm y)$ , $x^3 \pm y^3 = (x \pm y)(x^2 \mp xy + y^2)$ , and if $x + y + z = 0$ then $x^3 + y^3 + z^3 = 3xyz$ .

The worked solution

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← Expand (3x + 2y)² and (x - 3y)³.Show that if x + y + z = 0, then x³ + y³ + z³ = 3xyz. Use it to find 9³ + (-4)³ + (-5)³. →

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Factorise 27x³ + 64y³.

The worked solution

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