SOLUTION: simplify {{{ sqrt(45)-10/sqrt(5) }}}

Algebra ->  Radicals -> SOLUTION: simplify {{{ sqrt(45)-10/sqrt(5) }}}      Log On


   

Question 701399: simplify +sqrt%2845%29-10%2Fsqrt%285%29+
Found 2 solutions by Simnepi, MathTherapy:
Answer by Simnepi(216) About Me  (Show Source):
You can put this solution on YOUR website!
sqrt%2845%29-10%2Fsqrt%285%29
Because 45 is 9*5 we can re-write this assqrt%289%2A5%29
we can take out the sqrt%289%29 to give 3sqrt%285%29
so now we have
3sqrt%285%29-10%2Fsqrt%285%29 we can now get rid of the fraction by multiplying through by sqrt%285%29
this gives
%283sqrt%285%29%2Asqrt%285%29%29-%28%2810%2Fsqrt%285%29%29%2Asqrt%285%29%29 to give
3*5 - 10 = 5

Answer by MathTherapy(10719) About Me  (Show Source):
You can put this solution on YOUR website!
simplify +sqrt%2845%29-10%2Fsqrt%285%29+
====================================
The other person's answer, 15, is WRONG!!

sqrt%2845%29+-+10%2Fsqrt%285%29 = %28sqrt%2845%29%2Asqrt%285%29%29%2Fsqrt%285%29+-+10%2Fsqrt%285%29 = %28sqrt%289+%2A+5%29sqrt%285%29+-+10%29%2Fsqrt%285%29 = %28sqrt%289%29sqrt%285%29sqrt%285%29+-+10%29%2Fsqrt%285%29 = %283%285%29+-+10%29%2Fsqrt%285%29 = %2815+-+10%29%2Fsqrt%285%29 = 5%2Fsqrt%285%29 = %285%2Fsqrt%285%29%29%28sqrt%285%29%2Fsqrt%285%29%29 = 5sqrt%285%29%2F5 = cross%285%29sqrt%285%29%2Fcross%285%29 = highlight%28sqrt%285%29%29