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secondary 3 | A Maths
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Jolyn Tan
Jolyn Tan

secondary 3 chevron_right A Maths

How do you solve part c and e? Thank you!

Date Posted: 7 years ago
Views: 779

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Lim Jing Yu
Lim Jing Yu's answer
7 answers (A Helpful Person)
1st
Both questions can be solved using the same formula:
a^3 - b^3 = (a - b) ( a^2 + ab + b^2)
Hence simplify both questions to fit into the formula and it's solved.
i.e. 125x^3 - 64y^3 = (5x)^3 - (4y)^3, where a = 5x and b = 4y
Similarly, 216 - (3x - 4)^3 = 6^3 - (3x - 4)^3, where a = 6 and b = 3x - 4.
Good luck