Respuesta :
Answer:
B. x = 5 and y = -13
Step-by-step explanation:
Equating real parts, we have ...
... x + 4 = 9
... x = 9 - 4 . . . . subtract 4
... x = 5
___
Equating imaginary parts, we have ...
... yi +9i = -4i
... yi = -4i -9i = -13i . . . . subtract 9i
... y = -13 . . . . . . . . . . . divide by i
[tex](x+yi)+(4+9i)=9-4i \\\\x+4+yi+9i=9-4i\\\\x+4+(y+9)i=9-4i\\\\x+4=9 \wedge y+9=-4\\\\x=5 \wedge y=-13 \Rightarrow \text{B}[/tex]