Help with algebra Please!!!!!!?

Question

Hi everyone! I just wanted to know how to expand brackets when you have an equation like 4x-(x+3)=x-3. It's just mainly the first part of the equation that I'm stuck on so if you could please find the time to help me, it would really be appreciated. Thanks!!!

Hey I have another question, what if you have an equation to solve like 2x-3(x-3)=6x-5? How would you do that?

Answer 1

There's a "-" before the bracket, so every sign inside the bracket has to be reversed. So it turns out as
4x - x - 3 = x - 3
If there was a + before the bracket, then you wouldn't have to change anything.

Answer 2

Consider expanding the following:

2(x + 3) - here we are saying we have two lots of (x+3) so:
2(x+3) = (x+3) + (x+3) = x + 3 + x + 3 = 2x + 6

4(x - 7) - here we are saying we have 4 lots of (x - 7) so:
4(x - 7) = (x - 7) + (x - 7) + (x - 7) + (x - 7) = 4x - 28

You might have already spotted the pattern: when you multiply out bracket, you multiply all the terms (numbers, letters...) by the thing outside the bracket.

What about:

x(6 - y)? Well, following the same rule, we get:

x(6 - y) = 6x - xy.

Now, to your problem:

4x - (x + 3) = x - 3

Just looking at the brackets:

-(x+3). here, you can treat this like a minus one - that's all it is, so:

-(x+3) = -1*x + -1*3 = -x - 3

Now, substituting this into our equation, we get:

4x - x - 3 = x - 3

=> 3x - 3 = x - 3

=> 3x = x

=> 2x = 0

=> x = 0.

Hope that helps!

Answer 3

To expand anything in brackets, multiple what's inside the brackets by what's immediately outside e.g.

2(x+1) is equivalent to 2x + 2 as both the 'x' and the '1' are multiplied by the '2'.

-2(x+1) is equivalent to -2x - 2 as both the 'x' and the '1' are multiplied by the '-2'

In your example the '-(x+3)' is really '-1(x+3)' but the '1' is omitted to make it simpler to read.

Your equation expands to: 4x -x -3 = x + 3

(notice that the first 3 becomes negative as it is really '-1 * 3')

You can subtract the 'x' from '4x' to get '3x', giving: 3x - 3 = x + 3

Which simplifies to: 2x = 6, or x = 3

Answer 4

I'm not sure this is what you are asking, but I'll try:

You can always imagine a bracket is multiplied by one, so

4x-(x+3)=4x-x-3=x-3
4x-x-3+3=x-3+3
4x-x=x
3x=x?

I either goofed or the answer is x=0.

Hey, it's been a while since my last math class!

For your second problem [-3(x-3)]=-3x+9 Just substitute this into the problem.

Answer 5

First open the line bracket. Then the crescent. Then the double crescent, Last the square bracket. O. Kay ?
Here you have only one bracket. It goes like,
4x - x - 3 = x - 3; 2x = 0; x = 0.

Answer 6

This is a bit clearer if you can see that the expression can be written as 4x-1(x-3)=x-3
The expansion thus becomes 4x-1x+3=x-3 . This reduces to 3x+3=x-3, and further to3x-x=-3-3
2x=-6, x=-3

Answer 7

if the previous answer is correct about the signs in the brakets being reversed then the equation would be...
4x (x-3)=x-3
you expand and left with...4x (squared) - 12x=x-3
then you have to add 12 x form each side and since you have a - 12x then that esults in 0..
4x(squared) = 13x-3..13x is adding the 12 x to each side
leave it from there for you hope it helps

Answer 8

4x-(x+3)=x-3
This means 4x -1(x+3) = x-3
So you need to multiply -1 times everything inside the parentheses
So you get 4x -x -3 = x-3
Remember -times - and + times + always = +
and - times plus or plus times minus always gives -
x and 1x ar the same thing. x = +x.

2x-3(x-3)=6x-5
2x-3x +9 =6x -5
-x+9 =6x-5
-x-6x= -5-9
-7x = -14
x=2

Answer 9

4x - (x + 3) = x - 3
4x - x - 3 = x - 3
2x = 0

There is no solution to this problem, else, x = 0.

Answer 10

there is a -ve sign front of the bracet, so what you do is, change all the signs in the bracet oppostely

so it becomes

4x-x-3=x-3
3x-3=x-3
then so on ( i=hope u can solve this

kimYoonJin