Question 117926
{{{sqrt(5) -3*sqrt(20)+sqrt(45)}}} Start with the given expression



{{{sqrt(5)-3*2*sqrt(5)+sqrt(45)}}} Simplify {{{sqrt(20)}}} to get {{{2*sqrt(5)}}}. Note: If you need help with simplifying square roots, check out this <a href=http://www.algebra.com/algebra/homework/Radicals/simplifying-square-roots.solver> solver</a>.



{{{sqrt(5)-3*2*sqrt(5)+3*sqrt(5)}}} Simplify {{{sqrt(45)}}} to get {{{3*sqrt(5)}}}.



{{{sqrt(5)-6*sqrt(5)+3*sqrt(5)}}} Multiply 3 and 2 to get 6.

 

Since we have the common term {{{sqrt(5)}}}, we can combine like terms


{{{(1-6+3)sqrt(5)}}} Combine like terms. Remember, {{{5x+3x-4x=(5+3-4)x=4x}}}



{{{-2*sqrt(5)}}}


So {{{sqrt(5) -3*sqrt(20)+sqrt(45)}}} simplifies to {{{-2*sqrt(5)}}}. In other words,  {{{sqrt(5) -3*sqrt(20)+sqrt(45)=-2*sqrt(5)}}}