Question

(a-1)(a^2+a+1) - a^2(a-8) при a = 29

Answer 1

$(a-1)(a^2+a+1) - a^2(a-8)=a^3-1-a^3+8a^2=8a^2-1$
$a= frac{2}{9}$
$8a^2-1=8*( frac{2}{9} )^2-1=8* frac{4}{81}-1= frac{32}{81} -1=- frac{49}{81}$

$(a-b)(a^2+ab+b^2)=a^3-b^3$

Answer 2

Ответ: а^3-а^3+8а^2=-1+8а^2
при а=2/9
-1+8×2/9^2=-1+32/81=-81+32/81=-49/81