## Destinyyyy one year ago Memory refresher..

1. anonymous

Subtract 7-(-5+6i)-(-1-i)

2. welshfella

be careful with the signs remember that - * + = - and -*- = + when you are distributing the negative over the 2 parentheses

3. anonymous

Im assuming that your talking about the minus sign between the two parenthesis. The part that has me a bit stuck is the 7-. I know how to distribute the negative sign to others.

4. SolomonZelman

Ok, you got that $$i=\sqrt{-1}$$ , right?

5. SolomonZelman

or, is it just variable/

6. anonymous

Yes. This is complex numbers.

7. welshfella

the first negative is distributed about the first parentheses in the usual way

8. anonymous

The one behind the 7?

9. SolomonZelman

10. ikram002p

keep real part together and terms with " i " together this is all what you need to remember :)

11. welshfella

the one after the 7 Yes

12. ikram002p

i wrote art @SolomonZelman :P

13. SolomonZelman

despite that it's my 3rd language, I got good at it lately:)

14. SolomonZelman

in any case,

15. anonymous

7(5-6i)-(-1-i) Now I times 7 to the first parenthesis and distribute the negative to the second correct?

16. welshfella

if you like you can treat the - before the parentheses as -1 - so multiply everything in parentheses by -1

17. anonymous

36-41i

18. welshfella

7 - (-5 + 6i) = 7 + 5 - 6i

19. welshfella

distributing the negative over - 5 + 6i gives + 5 - 6i

20. welshfella

- you are not multiplying the -5 + 6i bt multiplying it by -1

21. welshfella

* not multiplying the -5 + 6i by 7 I meant to say

22. anonymous

Why not? I just get rid of the parenthesis by distributing the negative?

23. anonymous

I got 13-5i

24. welshfella

yes and the 7 isn't touched - it stays put

25. welshfella

7 + 5 - 6i - (-1 - i) = 12 - 6t + 1 + i = 13 - 5i

26. welshfella

right

27. anonymous

okay.

28. welshfella

good

29. SolomonZelman

actually, doesn't matter whether i is a variable or imaginary number, you get the same result.

30. SolomonZelman

well, not the same value, but a result that is recorded in the same way.