10!!!!!!!!!!!!!!!!!!!!

Question

10!!!!!!!!!!!!!!!!!!!!

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Answer 1

(а³-b³)/(√a-√b)  ÷ (a²+ab +b²) =
= (a-b)(a²+ab+b²) / (√a-√b)       *   1/(a²+ab+b²)  =
= (a-b)(a²+ab+b²) / (√a-√b)(a²+ab+b²)=
= (a-b) / (√a-√b)   =  
= ((√a)² -(√b)²) / (√a-√b)=
= (√a-√b)(√a+√b)  / (√a-√b)  =
= √a +√b