How do you simplify (3sqrtx - sqrty)(sqrtx-4sqrty)?

1 Answer
Jul 8, 2016

I found: 3x+4y-13sqrt(xy)

Explanation:

We can try multiplying the two brackets (distribute) to get:
(3sqrt(x)-sqrt(y))(sqrt(x)-4sqrt(y))=3sqrt(x)sqrt(x)-12sqrt(x)sqrt(y)-sqrt(x)sqrt(y)+4sqrt(y)sqrt(y)=
we can now add similar terms (in sqrt(x)sqrt(y)) and use the fact that sqrt(x)sqrt(x)=x or sqrt(y)sqrt(y)=y and write:

=3x-13sqrt(x)sqrt(y)+4y=3x+4y-13sqrt(xy)

...that is as far I can go!