Răspuns:
Sper ca te am ajutat
Explicație pas cu pas:
a. [tex](\frac{-4\sqrt{5} }{3} x \frac{\sqrt{7} }{2} a)x (\frac{-4\sqrt{5} }{3} x\frac{\sqrt{7} }{2} a)[/tex]
⇒[tex](\frac{-2\sqrt{5} }{3} x\sqrt{7a} ) x (\frac{-2\sqrt{5} }{3} x\sqrt{7a} )[/tex]⇒[tex](\frac{-2\sqrt{35a} }{3} )x(\frac{-2\sqrt{35a} }{3} )[/tex]⇒[tex]\frac{2\sqrt{35a} }{3} x\frac{2\sqrt{35a} }{3} =\frac{140a^{2} }{9}[/tex]
b.[tex](a+3)(a-3)=a^{2} -3^{2} = a^{2} -9[/tex]
c.[tex](2x+1)(2x-1)=2x^{2} -1^{2} =4x^{2} -1[/tex]
d.⇒[tex](5\sqrt{2x} )^{2} -2x5\sqrt{2x} x3\sqrt{3y}+(3\sqrt{3y} )^{2}[/tex]⇒[tex]25x 2x^{2} -30\sqrt{6xy} +9x3y^{2}[/tex]⇒[tex]50x^{2} -30\sqrt{6xy} +27y^{2}[/tex]
e.[tex](\frac{-2}{7} x\frac{7}{3} y)^{2}[/tex]⇒[tex](\frac{-2}{3} y)^{2}[/tex]⇒[tex]\frac{4}{9} y^{2}[/tex]
