Răspuns:
[tex]14\sqrt{3}-21\sqrt{6}[/tex]
Explicație pas cu pas:
[tex](4\sqrt{21}-6\sqrt{42}):2\sqrt{7}[/tex]
[tex]\frac{4\sqrt{21}-6\sqrt{42}}{2}*\sqrt{7}[/tex]
[tex]\frac{2(2\sqrt{21}-3\sqrt{42})}{2}*\sqrt{7}[/tex]
[tex](2\sqrt{21}-3\sqrt{42})*\sqrt{7}[/tex]
[tex]2\sqrt{21*7}-3\sqrt{42*7}[/tex]
[tex]2\sqrt{147}-3\sqrt{294}[/tex]
[tex]2*7\sqrt{3}-3*7\sqrt{6}=14\sqrt{3}-21\sqrt{6}[/tex]