Question 202863
{{{5*sqrt(-16)+3*sqrt(-81)}}} Start with the given expression.



{{{5*sqrt(-1*16)+3*sqrt(-1*81)}}} Factor



{{{5*sqrt(-1)*sqrt(16)+3*sqrt(-1)*sqrt(81)}}} Break up the roots



{{{5*i*sqrt(16)+3*i*sqrt(81)}}} Replace {{{sqrt(-1)}}} with "i"



{{{5*i*4+3*i*9}}} Take the square root of 16 to get 4. Take the square root of 81 to get 9.



{{{5*4*i+3*9*i}}} Rearrange the terms.



{{{20*i+27*i}}} Multiply



{{{47*i}}} Combine like terms.



So {{{5*sqrt(-16)+3*sqrt(-81)=47*i}}}