Solve Complex Number Equations: Ib & Ia

[DunceKirchhoff]

Ib= (-12.4-j6.88)-(9.57-j6.38)
Ib= -12.4-j6.88-9.57+j6.38
Ib=(-22-j0.5)A

Why does the -j6.38 become +j6.38?

Ia=(9.57-j6.38)-(0.454+j13)
Ia= 9.57-j6.38-0.454-j13

Why does the +J13 become -J13?

Thanks

 

[SteamKing]

Because -(a+b) = -a - b It's the same as -(a+b) = -1*(a+b)

Review your basic arithmetic (distributive property)

http://en.wikipedia.org/wiki/Distributive_property

 

[DunceKirchhoff]

So for the top one the two minuses become a positive?

 

[SteamKing]

Well, what is -1 * -1?

 

[DunceKirchhoff]

It equals 1.
Yip I get you thanks.

Its just the way it was laid out that got me.