View attachment 165852
mọi người giúp em vs ạ mai em ktra rồi
thay x bằng 64 vào ta có:
P=[tex](\frac{8}{60}+\frac{1}{6}).\frac{6}{2}[/tex]
=[tex]\frac{8+10}{60}.3[/tex]
=[tex]\frac{18}{20}[/tex]=[tex]\frac{9}{10}[/tex]
b,P=[tex](\frac{\sqrt{x}}{(\sqrt{x}-2)(\sqrt{x}+2)}+\frac{1}{\sqrt{x}-2}).\frac{\sqrt{x}-2}{2}[/tex]
=[tex](\frac{\sqrt{x}+\sqrt{x}+2}{(\sqrt{x}+2)(\sqrt{x}-2)}).\frac{\sqrt{x}-2}{2}[/tex]
=[tex]\frac{2.(\sqrt{x}+1)}{(\sqrt{x}-2)(\sqrt{x}+2)}.\frac{\sqrt{x}-2}{2}[/tex]
=[tex]\frac{\sqrt{x}+1}{\sqrt{x}+2}[/tex]