# multiply by reciprocal

• November 28th 2008, 09:16 AM
brentwoodbc
multiply by reciprocal
To get rid of the 1/2 how is it done?

2d+4c=1/2 4b+2a

is it

2/1(2d+4c)=2/1(1/2 4b+2a)
so
4d+8c=4b+2a

or

2/1(2d+4c)= (2/1)1/2 4b+2a
so
4d+8c=4b+2a

or something different?

• November 28th 2008, 09:49 AM
TheEmptySet
Quote:

Originally Posted by brentwoodbc
To get rid of the 1/2 how is it done?

2d+4c=1/2 4b+2a

is it

2/1(2d+4c)=2/1(1/2 4b+2a)
so
4d+8c=4b+2a

or

2/1(2d+4c)= (2/1)1/2 4b+2a
so
4d+8c=4b+2a

or something different?

Hello bentwoodbc,

I guess I'm unsure what you mean. Is this the problem

$2d+4c=\frac{1}{2}(4b+2a)$

if so you can use the distributive law to simplify

$2d+4c=\frac{1}{2}\cdot 4b+\cdot \frac{1}{2} 2a$

$2d+4c=2b+a$

if it is just $\frac{1}{2}4b=2b$

Good luck.