Salutare
Folosim proprietatile radicalilor adica :
[tex]\sqrt{(a)*b)} = \sqrt(a)*\sqrt(b)\\\\\sqrt(a/b) =\sqrt(a)/\sqrt(b)[/tex]
Si vom da si factor comun.
a)[tex]2*\sqrt{2}*\sqrt{5} -3*\sqrt{5} *\sqrt{2} +4*\sqrt{5} *3*\sqrt{2} -5*\sqrt{5} *4*\sqrt{2}[/tex]
Dam factor comun pe [tex]\sqrt{2}*\sqrt{5} \\[/tex] si rezulta :
[tex]\sqrt{2} *\sqrt{5} * (2-3+4*3-5*4)\\\sqrt{10} *(-1+12-20)\\\sqrt{10}*(11-20)\\\sqrt{10}*(-9)\\-9*\sqrt{10}[/tex]
b)[tex]\frac{\sqrt{21} }{\sqrt{7} } -5*\frac{\sqrt{15} }{\sqrt{5} } +2*3*\sqrt{3} -4*\frac{\sqrt{30} }{\sqrt{10} } \\\\\sqrt{3} -5*\sqrt{3} +6*\sqrt{3} -4*\sqrt{3}[/tex]
Dam factor comun pe [tex]\sqrt{3}[/tex] si rezulta :
[tex]\sqrt{3}*(1-5+2*3-4)\\\\\sqrt{3}*(1-5+6-4)\\\\\sqrt{3}*(-2)\\\\-2*\sqrt{3}[/tex]
