Răspuns:
[tex](3 \sqrt{7} - 50 \sqrt{7} ) + (3 \sqrt{7} - 5 \sqrt{7} + \sqrt{7} ) = ( - 47 \sqrt{7} ) + ( - \sqrt{7} ) = - 47 \sqrt{7} - 7 = - 48 \sqrt{7} [/tex]
