Răspunsuri

2014-09-18T22:03:10+03:00
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}.
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