Please help! Perform the indicated operation. Leave all answers in the form a + b i.
(1 - i ) (2 + 3 i )

a. -1 - 5 i
b. -1 + i
c. 5 + i
d. 5 - 5 i

Question

Please help! Perform the indicated operation. Leave all answers in the form a + b i. 
(1 - i ) (2 + 3 i ) 

a. -1 - 5 i
b. -1 + i 
c. 5 + i 
d. 5 - 5 i

hartnn · Answer

do u know this:
(a+b)(c+d)=ac+ad+bc+bd
?

anonymous · Answer

I'm familiar. Hmmm, so that's what I use?

hartnn · Answer

and also the fact that i*i = -1
just try it....

mathslover · Answer

$$\large{(1-i)(2+3i)=1(2+3i)-i(2+3i)}$$ 
$$\large{(1-i)(2+3i)=1(2)+1(3i)-i(2)-i(3i)}$$

this is the use of taht @IloveCharlie

mathslover · Answer

*that

anonymous · Answer

Hmm... :/

anonymous · Answer

d.

mathslover · Answer

what is i(3i) ?

mathslover · Answer

i * 3i = 3 i ^2 = 3(-1) = -3 

2+3i-2i+3 
5+i

anonymous · Answer

i(3i)=-3 @mathslover

anonymous · Answer

9+2i?

anonymous · Answer

:/

hartnn · Answer

@mathslover already gave u answer,see the comments....

anonymous · Answer

Yes but I can't match it up :/

hartnn · Answer

he gave u answer as 5+i,which is option c
here are all steps together:
(1−i)(2+3i)
=1(2)+1(3i)−i(2)−i(3i)
=2+3i-2i+3 
=5+i

anonymous · Answer

Oh I understood I just must have missed it. Thank you for explaining the steps BOTH of you I appreciate it

mathslover · Answer

Oh sorry yes :
i *3 i =3 i^2 = -3