Question 134295
{{{3*sqrt(7)-2*sqrt(28)}}} Start with the given expression



{{{3*sqrt(7)-2*2*sqrt(7)}}} Simplify {{{sqrt(28)}}} to get {{{2*sqrt(7)}}}. 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>.



{{{3*sqrt(7)-4*sqrt(7)}}} Multiply 2 and 2 to get 4.

 

Since we have the common term {{{sqrt(7)}}}, we can combine like terms



{{{(3-4)sqrt(7)}}} Combine like terms. 



{{{-1*sqrt(7)}}} Now simplify {{{3-4}}} to get {{{-1}}}



{{{-sqrt(7)}}} Simplify 




So {{{3*sqrt(7)-2*sqrt(28)}}} simplifies to {{{-sqrt(7)}}}. In other words,  {{{3*sqrt(7)-2*sqrt(28)=-sqrt(7)}}}