1)80³-50³=(8*10)³-(5*10)³=10³(8³-5³)=1000(8-5)(8²+8*5+5²)=<span><span>300*10(8²+8*5+5²)
</span> 2)87</span><span>³+32</span>³=(87+32)(87²-87*32+32²)=119(87²-87*32+32²)
3)75³+65³=(5*15)<span>³+(5*13)</span>³=5³(15³+13³)=5*25(15+13)(15²-15*13+13²)=
5*25*28(15²-15*13+13²)=700*5<span><span>(15²-15*13+13²)
</span>4)84³+24³ =.(12*7)³+(12*2)³=12³(7³+2³)=2³6³(7+2)(7²-7*2+2²)=8*216*9</span><span>(7²-7*2+2²)=</span>8*1944<span>(7²-7*2+2²)</span>
N1=1^2-1/2=1/2
n2=2^2-2/2=4-1=3
n3=3^2-3/2=9-3/2=15/2
1) 6(а-2,5b)
2) а(2+b)
3)7(am+bn)
Везде вынесли общий множитель.