Question

Simplify (2-3i)(7-4i)

Answer 1

use FOIL first then tell me what you got

Answer 2

14-8i-21i+12i?

Answer 3

you were right in the first three terms...last term is 12i^2 because it's i times i got it?

Answer 4

Yes.

Answer 5

Now what?

Answer 6

substitute i^2 into -1

Answer 7

now simplify since you know i^2 = -1

Answer 8

2-29i?

Answer 9

seems abt right

Answer 10

\[(a+bi)(c+di)=(ac-bd)+(ad+bc)i\] is another way to do it

Answer 11

and the way you should really learn at some point

Answer 12

Thank you for your help.

Answer 13

@satellite73 loves memorizing formulas i see...i believe in the KISS principle so i just do it traditionally :P

Answer 14

actually that is the definition
not a formula
if you see this topic in a later class that is what you will do, take my word for it

Answer 15

but if you do forget it...FOIL/distributive property is a good thing to back up to