SOLUTION: Simplify: (2radical sign5)(3radical sign5)-radical sign 45 I believe when the two expressions are multiplied I get 6 radical sign 5 but I'm not sure what to do with -radical sign

Algebra ->  Radicals -> SOLUTION: Simplify: (2radical sign5)(3radical sign5)-radical sign 45 I believe when the two expressions are multiplied I get 6 radical sign 5 but I'm not sure what to do with -radical sign      Log On


   

Question 6415: Simplify:
(2radical sign5)(3radical sign5)-radical sign 45
I believe when the two expressions are multiplied I get 6 radical sign 5 but I'm not sure what to do with -radical sign 45.
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
i assume you mean... %282sqrt%285%29%29%283sqrt%285%29%29-+sqrt%2845%29? If so, we get...

2%2A3%2Asqrt%285%29%2Asqrt%285%29+-+sqrt%2845%29
6%2Asqrt%285%29%2Asqrt%285%29+-+sqrt%2845%29
6%2A5+-+sqrt%2845%29 since sqrt%285%29%2Asqrt%285%29 is 5
30+-+sqrt%2845%29

ok, now for the sqrt%2845%29...

30+-+sqrt%289%2A5%29
30+-+sqrt%289%29sqrt%285%29
30+-+3sqrt%285%29 --> this is an answer or we could factorise further to give:
3%2810+-+sqrt%285%29%29

jon.