Question

Descompuneti in factori :

a) (x+ √2)^2 - 8

b) (2x+√3)^2 - 27

 

Answer 1

Folosim formula $a^{2} - b^{2}= (a-b)*(a+b)$
$( x+ \sqrt{2}) ^{2}-8= ( x+ \sqrt{2}) ^{2}-(2 \sqrt{2} )^{2}=$
$=(x+ \sqrt{2}-2 \sqrt{2} )*(x+ \sqrt{2}+2 \sqrt{2} )=(x- \sqrt{2} )(x+3 \sqrt{2} )$

Folosesti aceeasi formula si pt al doilea exercitiu si tii cont ca $27=(3 \sqrt{3} )^{2}$.