a+2b=5 then show that a cube+8(b)cube+30ab=125

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a+2b=5, so (a+2b)3=125=a3+6a2b+12ab2+8b3,

a3+6a2b+12ab2+8b3=a3+8b3+6ab(a+2b)=125,

a3+8b3+6ab(5)=125=a3+8b3+30ab QED

by Top Rated User (1.1m points)

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