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Question
Simplify:
\[\frac{8 x^3 - 27 y^3}{4 x^2 - 9 y^2}\]
Solution
It is known that,
a2 − b2 = (a + b) (a − b)
a3 − b3 = (a − b)(a2 + ab + b2)
\[\ \frac{8 x^3 - 27 y^3}{4 x^2 - 9 y^2}\]
\[ = \frac{\left( 2x \right)^3 - \left( 3y \right)^3}{\left( 2x \right)^2 - \left( 3y \right)^2}\]
\[ = \frac{\left( 2x - 3y \right)\left[ \left( 2x \right)^2 + \left( 2x \right) \times \left( 3y \right) + \left( 3y \right)^2 \right]}{\left( 2x + 3y \right)\left( 2x - 3y \right)}\]
\[= \frac{\left(2x - 3y \right)\left(4 x^2 + 6xy + 9 y^2 \right)}{\left( 2x + 3y \right)\left(2x - 3y \right)}\]
\[= \frac{4 x^2 + 6xy + 9 y^2}{\left(2x + 3y \right)}\]
RELATED QUESTIONS
Simplify:
\[\frac{x^2 - 5x - 24}{\left( x + 3 \right)\left( x + 8 \right)} \times \frac{x^2 - 64}{\left( x - 8 \right)^2}\]
Simplify:
\[\frac{4 x^2 - 11x + 6}{16 x^2 - 9}\]
Simplify:
\[\frac{a^3 - 27}{5 a^2 - 16a + 3} \div \frac{a^2 + 3a + 9}{25 a^2 - 1}\]
Simplify:
\[\frac{1 - 2x + x^2}{1 - x^3} \times \frac{1 + x + x^2}{1 + x}\]
Factorise:
27m3 − 216n3
Factorise:
8p3 −\[\frac{27}{p^3}\]
Factorise:
`16a^3 - 128/b^3`
Simplify:
(3xy − 2ab)3 − (3xy + 2ab)3
Factorise: x3 - 8y3
Factorise the following:
a6 – 64
