what is the following quotient? 2/ square root 13 + square root 11
A.
[tex] \sqrt{13} - 2 \sqrt{11} [/tex]
B.
[tex] \sqrt{13} + \sqrt{11} \div 6[/tex]
C.
[tex] \sqrt{13} + \sqrt{11} \div 12[/tex]
D.
[tex] \sqrt{13} - \sqrt{11} [/tex]

Respuesta :

Given : [tex]\frac{2}{\sqrt{13}+\sqrt{11}}[/tex]

[tex]\mathrm{Multiply\:by\:the\:conjugate}\:\frac{\sqrt{13}-\sqrt{11}}{\sqrt{13}-\sqrt{11}}[/tex]

[tex]=\frac{2\left(\sqrt{13}-\sqrt{11}\right)}{\left(\sqrt{13}+\sqrt{11}\right)\left(\sqrt{13}-\sqrt{11}\right)}[/tex]

\left(\sqrt{13}+\sqrt{11}\right)\left(\sqrt{13}-\sqrt{11}\right)

[tex]\mathrm{Apply\:Difference\:of\:Two\:Squares\:Formula:\:}\left(a+b\right)\left(a-b\right)=a^2-b^2[/tex]

[tex]a=\sqrt{13},\:b=\sqrt{11}[/tex]

[tex]=\left(\sqrt{13}\right)^2-\left(\sqrt{11}\right)^2[/tex]

[tex]\left(\sqrt{13}\right)^2-\left(\sqrt{11}\right)^2=13-11=2[/tex]

[tex]=\frac{2\left(\sqrt{13}-\sqrt{11}\right)}{2}[/tex]

[tex]\mathrm{Divide\:the\:numbers:}\:\frac{2}{2}=1[/tex]

[tex]=\sqrt{13}-\sqrt{11}[/tex]

Therefore, correct option is [tex]D.\\\sqrt{13} - \sqrt{11}[/tex]