Please Solve with working out?

Question

3+j7 / 6-j2

I don't understand it and someone has already tried but i am hopeless. Thanks

No they are cartesian complex numbers

Answer 1

I am assuming you are in electrical engineering and using j = i = sqrt(-1)

Then we have:
(3+j7))/(6-j2) = [3+j7)(6+j2)][(6-j2)(6+j2)
= (18 + j6 +j42 -14j^2)/(36+4)
= (32+j48)40
=(4 + j12)/5

Answer 2

If you have
3 + 7j / 6 - 2j
and you want to solve/simplify, you have to multiply the top and the bottom by the positive version of the denominator.

What?

You have to multiply the equation by
6 + 2j / 6 + 2j
because it will get rid of the complex number in the denominator, and it's the same as multiplying the equation by one (because the numerator and denominator are the same, right?)

So when you do that you get:

(3 + 7j) (6 + 2j)
----------- * -----------
(6 - 2j) (6 + 2j)

then

18 + 6j + 42j +14(-1)
-----------------------------
36 - 4(-1)

Remeber, j*j = -1
then

18-14 + 6j+42j
---------------------
36+4

then

4+48j
--------
40

Divide the top and bottom by 4 and you get

1+12j
--------
10

and that's your final answer. Yay!

Answer 3

If I'm reading your equation right and j is a variable... and its equal to 0 and your solving for j... then j = 3/7... of course thats probably not what your looking for...