Question

Algebra 2 Complex Numbers
Help if you can
Simplify the expression?
-6+i/-5+i
A. 31+i/26
B. 29+i/26
C.31+i/24
D.31+11i/26

Answer 1

multiply the numerator and denominator by the conjugate of the denominator

Answer 2

What is the conjugate?

Answer 3

look at the denominator

-5+i

change the sign in the middle

Answer 4

So is would be -5-i

Answer 5

right, the conjugate of -5+i is -5-i

now, go back to the original expression

(-6+i)/(-5+i)

multiplying the numerator and denominator by (-5-i) gives us

[(-5-i)(-6+i)] / [(-5+i)(-5-i)]

simplify

Answer 6

hint: use the foil method on the numerator and denominator

Answer 7

i got i^2+30+i/i^2+25

Answer 8

almost, check your denonimator again

Answer 9

ok i checked it and it gave me the same thing for the denominator -i^2+25

Answer 10

right, there was a negative sign in front of i^2 that you missed before

so we have (i^2+30+i)/(-i^2+25)

we can rewrite this if we recognize that i^2 = -1
can you try substituting -1 for i^2 into your expression now?

Answer 11

So i would replace -1 with all the i^2

Answer 12

yes, whenever you see "i^2" you can replace it with -1

Answer 13

29+i/24

Answer 14

almost but not quite

check your denominator again

Answer 15

-i^2+25 = ?

Answer 16

did i mess up with the double negative in the denominator

Answer 17

yes

Answer 18

-i^2+25 = -(-1) + 25 = ?

Answer 19

ok it would be B. 29+i/26

Answer 20

yeah! good job

Answer 21

Thankyou for helping me

Answer 22

@Saiyan uh, small correction, I made a mistake with the numerator

the numerator should be 30+i-i^2, giving is (31+i)/(26), sorry > >

Answer 23

ok thx