# Complex Number problem

#### Ixnay

##### New member

(-6i + 2) (7+3i)

I foil it out to -42i - 18i2 +14+6i
Does a negative i squared turn out to be a positive number? because i squared is equal to -1.
If I do that it solves out to be -36i + 32 which is marked wrong.
He wrote on my paper:
-6i+14+6i

#### galactus

##### Super Moderator
Staff member
$$\displaystyle \L\\18+14-42\imath+6\imath$$

$$\displaystyle \L\\32-36\imath$$ is the answer I get.

#### Denis

##### Senior Member
Your teacher gave answer for: -6i + 2(7 + 3i); must have been drunk :shock:

#### soroban

##### Elite Member
Ixnay said:
$$\displaystyle (-6i\,+\,2)(7\,+\,3i)$$

He wrote on my paper: -6i + 14 + 6i . . . are you sure?

Maybe your teacher is from Gamma Hydra IV
. . where the rules of math change on alternate Tuesdays.