How do you simplify (√2+√5) /( √2-√5)?

1 Answer
Mar 16, 2018

The simplified expression is -(7+2sqrt10)/37+2103.

Explanation:

color(white)=(sqrt2+sqrt5)/(sqrt2-sqrt5)=2+525

=((sqrt2+sqrt5))/((sqrt2-sqrt5))color(red)(*((sqrt2+sqrt5))/((sqrt2+sqrt5)))=(2+5)(25)(2+5)(2+5)

=((sqrt2+sqrt5)(sqrt2+sqrt5))/((sqrt2-sqrt5)(sqrt2+sqrt5))=(2+5)(2+5)(25)(2+5)

=((sqrt2+sqrt5)(sqrt2+sqrt5))/(sqrt2^2+sqrt2sqrt5-sqrt2sqrt5-sqrt5^2)=(2+5)(2+5)22+252552

=((sqrt2+sqrt5)(sqrt2+sqrt5))/(2color(red)cancelcolor(black)(+sqrt10-sqrt10)-5)

=((sqrt2+sqrt5)(sqrt2+sqrt5))/(2-5)

=((sqrt2+sqrt5)(sqrt2+sqrt5))/(-3)

=(sqrt2^2+sqrt2sqrt5+sqrt2sqrt5+sqrt5^2)/(-3)

=(2+sqrt10+sqrt10+5)/(-3)

=(2+2sqrt10+5)/(-3)

=(7+2sqrt10)/(-3)

=-(7+2sqrt10)/3

This is the answer. You can verify using a calculator:

![https://www.desmos.com/calculator](useruploads.socratic.org)