Question

Rationalize the denominator of (click photo)

Answer 1

`(√(-49))/((7-2i)-(4+9i))=\\ (√(-1*7*7))/(3-11i)=\\ (7i)/(3-11i)*(3+11i)/(3+11i)=\\ ((7i)*(3+11i))/(3^2-(11i)^2)=\\ (21i+77i^2)/(9+121)=\\ (21i-77)/(130)=\\ (-77+21i)/(130)`

so it is the last option