Lim Jing Yu's answer to Jolyn Tan's Secondary 3 A Maths question.
done
{{ upvoteCount }} Upvotes
clear
{{ downvoteCount * -1 }} Downvotes
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
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
Date Posted:
7 years ago
360 Tutoring Program