Posted by Nayla on .
Does (7/4i1) symplify to be 7(1+4i)/18

Math 
drwls,
Not quite. Your parenthese seem to be in the wrong place, and your math is wrong.
7/(4i1)= 7(4i+1)/[(4i+1)(4i1)]
= 7(4i +1)/(17)
= (7/17)(1+4i) 
Math 
Nayla,
These are complex numbers by the way.

Math 
Nayla,
Thanks

Math 
Nayla,
why is the 1+4i on the side of the fraction and not on the top with the 7

Math 
MathMate,
(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,
is (7/17)(28/17i) the same thing

Math 
MathMate,
"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 squareroot 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)*(14i)=17 in the denominator, thereby rationalizing it.