[Extra easy]Simplify

• March 11th 2008, 10:33 AM
Hanga
[Extra easy]Simplify
Hi all, really need some help with this! :)
I know it's super duper easy but I won't get this without a proper explenation, please help me :)

Okay so we are supposed to simplify this;

4a/5 * 15/2a

I think I know how to do it in theory but I just can't seem to get the right answer. Im thinking of inverting the first one and then multiplying the second one by 2 in order to get the same nominator, but it's still not right.

Just for the heck of it i'd like some help with this one aswell. It's the same thing - Simplify

2/9z * 3z^2/10
• March 11th 2008, 10:38 AM
colby2152
Quote:

Originally Posted by Hanga
Hi all, really need some help with this! :)
I know it's super duper easy but I won't get this without a proper explenation, please help me :)

Okay so we are supposed to simplify this;

4a/5 * 15/2a

I think I know how to do it in theory but I just can't seem to get the right answer. Im thinking of inverting the first one and then multiplying the second one by 2 in order to get the same nominator, but it's still not right.

Just for the heck of it i'd like some help with this one aswell. It's the same thing - Simplify

2/9z * 3z^2/10

$\frac{4a}{5}*\frac{15}{2a} = \frac{60a}{10a} \Rightarrow 6$

$\frac{2}{9z}*\frac{3z^2}{10} = \frac{6z^2}{90z} \Rightarrow \frac{z}{15}$
• March 11th 2008, 10:39 AM
topsquark
Quote:

Originally Posted by Hanga
Hi all, really need some help with this! :)
I know it's super duper easy but I won't get this without a proper explenation, please help me :)

Okay so we are supposed to simplify this;

4a/5 * 15/2a

I think I know how to do it in theory but I just can't seem to get the right answer. Im thinking of inverting the first one and then multiplying the second one by 2 in order to get the same nominator, but it's still not right.

Just for the heck of it i'd like some help with this one aswell. It's the same thing - Simplify

2/9z * 3z^2/10

$\frac{4a}{5} \cdot \frac{15}{2a}$

$= \frac{4a \cdot 15}{5 \cdot 2a}$

Start looking for factors common to the numerator and denominator. The most easily spotted is that variable a. We also have that 5 divides 15 evenly and 2 divides 4 evenly:
$\frac{(2 \cdot 2) \cdot a \cdot (5 \cdot 3)}{5 \cdot 2 \cdot a}$

Now cancel out the common factors:
$= \frac{2 \cdot 3}{1} = 6$

-Dan
• March 11th 2008, 10:42 AM
Hanga
(Swear) thats some really fast and very good help.

THANKS ALL FOR THIS! IT HELPS ALOT! :D
• March 11th 2008, 10:44 AM
colby2152
Quote:

Originally Posted by Hanga
(Swear) thats some really fast and very good help.

THANKS ALL FOR THIS! IT HELPS ALOT! :D

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