Răspuns:
25/a 876
25/b -204
26/a 168
26/b
Explicație pas cu pas:
75/a)
[tex]7\sqrt{20} (\sqrt{1125} -\sqrt{2205} )+6\sqrt{192}( \sqrt{1083}-\sqrt{300})=\\\\7\sqrt{20} (15\sqrt{5} -21\sqrt{5} )+6 * 8\sqrt{3}( 19\sqrt{3}-10\sqrt{3})=\\7\sqrt{20} * (-6\sqrt{5} )+6 * 8\sqrt{3} * 19\sqrt{3}=\\-7 *2\sqrt{5} * 6\sqrt{5} + 6 * 8 *3 *9=\\-7 *2*5*6+ 1296=\\-420 +1296=\\875[/tex]
25/b)
[tex]4\sqrt{12} (\sqrt{2028} -\sqrt{2700} ) - 3\sqrt{8} (\sqrt{968} -\sqrt{338})=\\4\sqrt{12} (26\sqrt{3} -30\sqrt3} ) - 3 * 2\sqrt{2} (22\sqrt{2} -13\sqrt{2})=\\4\sqrt{12} * (-4\sqrt{3}) - 3 * 2\sqrt{2} 9\sqrt{2}=\\-4 * 2\sqrt{3} * 4\sqrt{3} - 3 * 2*2 * 9=\\-4*2*3*4-108=\\-96-108=\\-204[/tex]
26/a)
[tex]\sqrt{98} (3\sqrt{242} -5\sqrt{32} + 3\sqrt{50} -2\sqrt{128} )=\\7\sqrt{2} (33\sqrt{2} -5*2^{2}\sqrt{2} + 15\sqrt{2} -2^{4} \sqrt{2} )=\\7\sqrt{2} (33\sqrt{2} -20\sqrt{2} + 15\sqrt{2} -16 \sqrt{2} )=\\7\sqrt{2}*12\sqrt{2}=\\7*2*12=\\168[/tex]
26/b)
[tex]\sqrt{125} (2\sqrt{27} -5\sqrt{48} -3\sqrt{147} +9\sqrt{300} )=\\5\sqrt{5} (6\sqrt{3} -20\sqrt{3} -21\sqrt{3} +90\sqrt{3} )=\\5\sqrt{5} * 55\sqrt{3}=\\275\sqrt{15}[/tex]
