ALGEBRA II HELP: Which of the following is the conjugate of 10 − 3i?

Question

anonymous · Answer

change the sign in front of the imaginary part to find the conjugate

anonymous · Answer

(a + bi and (a - bi) are conjugates

anonymous · Answer

It would be 10+3i
For example Conjugates:
3-2i, 3+2i

campbell_st · Answer

remember part of the general quadratic formula   

$$-b \pm \sqrt{b^2 - 4ac}$$

so if you think about 

$$3 \pm \sqrt{-4} = 3 \pm 2i$$

so the integer doesn't change its just the sign of the imaginary part

campbell_st · Answer

its also like the difference of 2 squares 

how do you get a 2 term quadratic

(a -b)(a +b) = a^2 - b^2

iwanttogotostanford · Answer

sorry, my wi-fi went out for awhile 
@campbell_st  @twistnflip @peachpi

iwanttogotostanford · Answer

so i would want to do the opposite for this one?

iwanttogotostanford · Answer

what is the first step?

anonymous · Answer

Yes the conjugates are easy. just switch the sign from positive to negative or vice versa.
Here the conjugate is 10+3i

iwanttogotostanford · Answer

so it would be 13i?

iwanttogotostanford · Answer

wow I'm being stupid

anonymous · Answer

Nope do you have answer choices. It wouldn't be 13i because you can't add the two terms because one has a variable and the other does not lol

anonymous · Answer

The answer is 10 + 3i <-- Final answer

iwanttogotostanford · Answer

i get it the question was just asking for the conjugate so its 10+3i

iwanttogotostanford · Answer

my answer choices are

iwanttogotostanford · Answer

10 + 3i
 10 − 3i
 3 + 10i
 3 − 10i

anonymous · Answer

a.

anonymous · Answer

Make sense?

iwanttogotostanford · Answer

thanks for helping me better understand, everyone!

iwanttogotostanford · Answer

yep, makes perfect sense