Question

Help! Rationalize the denominator of http://prntscr.com/94d95u

Answer 1

@jigglypuff314

Answer 2

easy:
first of all you need to simplify it:
7-2i-4-9i=3-11i


now we have \[\frac{ \sqrt{-49} }{ 3-11i }=\frac{ i \sqrt{49} * (3+11i) }{ (3-11i)*(3+11i) }=\frac{ 3i \sqrt{49}-11 \sqrt{49} }{ 3+121}\]=\[\frac{ 3i \sqrt{49} -11 \sqrt{49} }{ 124 }\]

Answer 3

So now what? My answers are http://prntscr.com/94db9c .

Answer 4

woopers i made a mistake

it should be \[\frac{ 3i \sqrt{49} -11 \sqrt{49} }{ 9+121 }=\frac{ 3i \sqrt{49} -11 \sqrt{49} }{ 130 }=\frac{ 21i-77 }{ 130 }\]

Answer 5

Oh! Thanks!