# '　a⁴/(a - b)(a - c) + b⁴/(b - c)(b - a) + c⁴/(c - a)(c - b) =　　　　.?

• '　a⁴/(a - b)(a - c) + b⁴/(b - c)(b - a) + c⁴/(c - a)(c - b) =　　　　.?

a⁴（b-c）+b⁴（c-a）+c⁴（a-b）は、因数分解出来ますか？ a⁴(b－c)+b⁴(c－a)+c⁴(a－b)＝a⁴(b－c) ...
Positive: 31 %
Here is an alternative solution to Kb's: WLOG, assume a ≤ b ≤ c. Apply the rearrangement inequality to the 4 sets {a, b, c}, {a, b, c}, {b, c, a}, {c ...
Positive: 28 %

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set notation. pronunciation. meaning. Venn diagram. answer. A U B "A union B" everything that is in either of the sets {1, 2, 3} A ^ B
Positive: 31 %
Positive: 26 %
$$A⊆C,B⊆D \quad ⇒ \quad A \times B \subseteq C \times D \tag{1}$$ How do you prove such an implication ? You assume the left-hand side to be true.