+0  
 
+1
102
3
avatar

I want the answer pls !!

off-topic
 Nov 26, 2019
edited by Guest  Nov 26, 2019
 #1
avatar+8810 
+3

\(3(4x-2y)-2(3x+y) \)

\(=12x-6y-6x-2y\\ \color{blue}=6x-8y\)

 Nov 26, 2019
edited by asinus  Nov 26, 2019
 #2
avatar+998 
0

Do you know how to distribute?

I think you do, or else you wouldn't get this problem.

Asinus got this correct with a well-thought out explanation, but just if you don't understand distributive, here I am.

 

3(4x-2y) means 3*4x+3*(-2y). We multiply the outside value, 3, by each term inside the parenthesis.

The equation then becomes \(12x-6y-6x-2y\)

6x-8y.

 

You are very welcome!

:P

 Nov 26, 2019
 #3
avatar+106954 
+1

Thanks Coolstuff, I like your explanation.    cool

 

Since you are interested in teaching I thought you might be interested in alternate techniques .

This is how I would do it if I was serioulsy teaching someone about expanding brackets.

 

I'd talk about the area of a rectangle.  So a rectangle with sides 2 and 3 would have an area of  2*3 = 6

I'd draw that

 

Then I would move onto an algebraic example.  I would start with one that only had plus signs but I have drawn a representation of the first half of this problem.  

3(4x-2y) 

 

So 

    \(3(4x-2y)\\=12x+-6y\\=12x-6y\)

Melody  Nov 26, 2019

24 Online Users