Posted by jason silverman on .
Combine the radicals
sqrt 72 + sqrt 18
6sqrt7  4sqrt7
Multiply & express in simplest form
sqrt5 x sqrt20
1/3sqrt18 x sqrt16
Divide & express in simplest form
sqrt80 / sqrt5
sqrt150 / sqrt3
Rationalize the denominator
5
/
2sqrt3
6
/
sqrt7+2
3
/
sqrt6
2+sqrt3
/
4sqrt3

math b 
Damon,
I will do the first one and the last one, you do the rest.
sqrt 72 + sqrt 18
=
sqrt (18*4) + sqrt 18
=
2 sqrt 18 + 1 sqrt 18
=
3 sqrt (3*3*2)
=
9 sqrt 2

(2+sqrt 3) (4+sqrt3)
/
(4sqrt 3) (4+sqrt3)
=
(8 +6sqrt 3 + 3 )
/
(163)
=
(11 +6 sqrt 3)
/
13 
math b 
jason silverman,
is there a way that the 1/3sqrt18 x sqrt16 problem can be solved
150 / 3
and
6
sqrt7 + 2
i'm having trouble with those. 
math b 
drwls,
If you mean (1/3)sqrt18 x sqrt16, that is (1/3)sqrt(9*2)* 4 = 4 sqrt 2
Surely you know what 150/3 is.