View Full Version : Solve it :-

Amit28it

11-10-2011, 01:31 PM

I am trying to simplify the following equation:

[3(x + 2) + 2x] - [4(y + 2) - 3(y - 2)]

This is how I'm processing it:

[3x + 6 + 2x] - [4y + 8 - 3y + 6]

[5x + 6] - [14 + y]

5x + 6 - 14 + y = 5x + y -8

However, the text gives the answer as:

5x - y - 8

So what am I doing wrong? Thanks.

Architect

11-12-2011, 05:15 AM

When you reached here:

[5x + 6] - [14 + y]

5x + 6 - 14 + y = 5x + y -8

You did not distribute the negative one to y.

So, it should be:

5x + 6 - 14 - y = 5x - y -8

Amit28it

11-14-2011, 12:01 PM

When you reached here:

[5x + 6] - [14 + y]

5x + 6 - 14 + y = 5x + y -8

You did not distribute the negative one to y.

So, it should be:

5x + 6 - 14 - y = 5x - y -8

Can you explain it in broad way ????????

Plz it will help me in solving other questions.

Thanks .

Architect

11-15-2011, 03:00 PM

I'll try my best Herr or Frau Amit.

[3(x + 2) + 2x] - [4(y + 2) - 3(y - 2)]

First we do our order of operations:

______________

Parenthesis

Exponents

M-D: multiplication and division

A-S: addition and subtraction

______________

So, in our equation: [3(x + 2) + 2x] - [4(y + 2) - 3(y - 2)] , we have P, M, and A-S

First tackle the parenthesis'

[3(x + 2) + 2x]

Distribute 3 to (x+2) by multiplication and end up with:

[3x+6+2x].

Same Here:[4(y + 2) - 3(y - 2)]. Distrubte 4 to (y+2) and 3 to (y-2) by multiplication and receive:

[(4y+8)-(3y-6)] But notice the negative in front of (3y-6). You should treat it as -1(3y-6) //this is where you messed up.

so distribute -1 to (3y-6) by multiplication and get:

[(4y+8)+(-3y+6)]

______________

Now we do addition (or subtraction) of like terms:

[3x+6+2x] 3x and 2x are like terms so add.

[5x+6]

Now [(4y+8)+(-3y+6)]: 4y and -3y are like terms, add. 8 and 6 are like terms, add.

[y+14]

________

Now we do the final calculation:

[5x+6]-[y+14] : Notice you have that pesky negative infront of [y+14] again. treat it as -1(y+14)

distrubte -1 to (y+14) by multiplication

[-y-14]

add like terms

5x-y-8

If I did not explain it well, please tell me which part. or if you would like another example.

Enjoy, or don't

TommyRiordan

09-14-2012, 05:31 AM

[3(x + 2) + 2x] - [4(y + 2) - 3(y - 2)]

= [ 3x + 6 - 4y - 8 - 3y + 6]

= [ 3x -7y +4]