Question

Efectuati:
b) (√2- √3) la a treia;
c) (3√5+1) la a treia
d) (2+√3) la a treia;
Va rog frumos ajtatima

Answer 1

folosim formulele de calcul prescurtat
(a-b)³=a³-3a²b+3ab²-b³
(a+b)³=a³+3a²b+3ab²+b³
b) (√2-√3)³=(√2)³-3·(√2)²·√3+3·√2·(√3)²-(√3)³=√8-3·2·√3+3·√2·√8-√27=2√2-6√3+3√2·3-3√3=2√2-6√3+9√2-3√3=11√2-9√3

c) (3√5+1)³=(3√5)³+3·(3√5)²·1+3·3√5·1²+1³=3³√5³+3·9·5+9√5+1=27·5√5+135+9√5+1=135√5+9√5+136=144√5+136

d)(2+√3)³=2³+3·2²·√3+3·2·√3²+√3³=8+12√3+18+3√3=26+15√3