Question

Scrie urmatiarele numere ca suma de doua cuburi perfecte: a) 9^7; b) 28^28; c) 35^19

Answer 1

9^7 = 9^6 × 9 = (9^2)^3 × (1^3 + 2^3) =

= (81 × 1)^3 + (81 × 2)^3 =

= 81^3 + 162^3
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28^28 = 28^27 × 28 =

= (28^9)^3 × (1^3 + 3^3) =

= (28^9 × 1)^3 + (28^9 × 3)^3 =

= (28^9)^3 + (28^9 × 3)^3
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35^19 = 35^18 × 35 = (35^6)^3 × (2^3 + 3^3) =

= (35^6 × 2) + (35^6 × 3)^3
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