SOLUTION: On my worksheet, it has subtracting and addition. like, (-6+12i)+(4-i) I was explained the addition, now it is easy to me. but my question is...should i do it differently if i

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: On my worksheet, it has subtracting and addition. like, (-6+12i)+(4-i) I was explained the addition, now it is easy to me. but my question is...should i do it differently if i      Log On


   

Question 181595: On my worksheet, it has subtracting and addition.
like, (-6+12i)+(4-i)
I was explained the addition, now it is easy to me.
but my question is...should i do it differently if it says subtract?
like...
(3-i)-(-4+9i)


do you do it differently than the addition one?
Found 2 solutions by solver91311, stanbon:
Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


The simple answer is never subtract. Always add the additive inverse. So, instead of:



Write:



Use the distributive property:



And now you can add just like before.


John

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
(-6+12i)+(4-i)
You cobine the Real Number parts and you cobine the imaginary number parts:
= (-6+4) + (12i - i)
= -2 + 11i
----------------
Ifyou were subtracting it would go like this:
(-6+12i)-(4-i)
= (-6-4)+(12i + i)
= -10 + 13i
================
Cheers
Stan H.