Posted by **Nayla** on Monday, November 23, 2009 at 10:35am.

Does (-7/4i-1) symplify to be -7(1+4i)/18

- Math -
**drwls**, Monday, November 23, 2009 at 11:43am
Not quite. Your parenthese seem to be in the wrong place, and your math is wrong.

-7/(4i-1)= -7(4i+1)/[(4i+1)(4i-1)]

= -7(4i +1)/(-17)

= (7/17)(1+4i)

- Math -
**Nayla**, Monday, November 23, 2009 at 11:45am
These are complex numbers by the way.

- Math -
**Nayla**, Monday, November 23, 2009 at 11:45am
Thanks

- Math -
**Nayla**, Monday, November 23, 2009 at 11:54am
why is the 1+4i on the side of the fraction and not on the top with the 7

- Math -
**MathMate**, Monday, November 23, 2009 at 1:11pm
(7/17)(1+4i) is the same as 7(1+4i)/17.

I too think it is simpler to write it as DRWS did, where the numeric fraction precedes the algebraic part.

- Math -
**Jaison**, Monday, November 23, 2009 at 1:18pm
is (7/17)-(28/17i) the same thing

- Math -
**MathMate**, Monday, November 23, 2009 at 2:42pm
"is (7/17)-(28/17i) the same thing "

No it is not.

(7/17)*(1+4i)

=(7/17)*1 + (7/17)*4i

=(7/17) + 28i/17

But this is not a simplified version.

In any case the object is to remove the "i" from denominator, or "rationalizing the denominator". Some teachers may consider it incomplete if square-root signs or "i" appear in the denominator.

The reason that the numerator and denominator were multiplied by (1+4i) was to create the product (1+4i)*(1-4i)=-17 in the denominator, thereby rationalizing it.

## Answer this Question

## Related Questions

- math - symplify the expression if possible: e^3
- mzth - how to symplify fractions fast
- pre algebra - symplify the following expression (3z)with exponent 0
- Math - Symplify (radical x/8) is the answer x (radical 2)/4
- Math - Symplify (radical x/8) is the answer x (radical 2)/4 i put it to be (x/2...
- Math...For All Math Tutors - I would like to know how many of the people ...
- math - all i can say is math stinx dont mess with math. without math, a lot of ...
- math - I just do not understand how to figure this out. Find the number of ...
- English Grammar - A: What time is your math/Math class? B: At eleven forty-five...
- Math - Is IB Math Studies the same as Pre-Calculus? I heard that IB Math Studies...

More Related Questions