Freaky Deaky Algebra Homework?

Question

I have holiday Maths homework and I want to get it done now so I don't have to worry about it, but I don't understand these questions:
3(4-x)-6(4-3x)=3
and
7(3-2x)-2(8-5x)=x
and
4(5x-1)+3(1-7x)=x

Can you exlain each section properly, then I can do the rest of the questions on the sheet. BTW You have to work out the value of 'x'. The first person whose answer I understand willl get 10 points.

Message to Peatargryfin ((or w/e the name is)): Well Duh!!!

Thankyoo to everyone who has answered! You made it a lot easier but now I don't know who to pick as best answer! I think I will pick 'Dogsafire'

I've got another question! It's:
4(5x-1)+3(1-7x)=xPlease help, I'm really confused!

Answer 1

The first thing you need to do is simplify each statement

3(4-x)-6(4-3x)=3
12-3x-24+18x=3

Combine like terms
-3x+18x=3-12+24
15x = 15

And then solve for x
x = 1

Next
7(3-2x)-2(8-5x)=x
Simplify
21-14x-16+10x=x
Combine
21-16=x+14x-10x
5=5x
Solve
x=1

4(5x-1)+3(1-7x)=x
Simplify
20x-4+3-21x=x
Combine
20x-21x-x=4-3
-2x=1
Solve
x=-1/2

Answer 2

In each case you want to end up with something that says "x=[some number]".
So, everything you do is going to involve putting all the 'x's on one side of the equation, and everything that isn't 'x' on the other, right?
The fact that all these equations have a lot of terms isn't important - it's just to intimidate you and make you think it's more difficult than it really is. So let's take a look:
When you see a term that includes parentheses () you can multiply the bits inside the parentheses by whatever is outside; so 3(4-x) is the same as (3*4-3*x). Similarly, 6(4-3x) is the same as (6*4-6*3x),
When you finish converting the parentheses, here's what you have:
(3*4 - 3*x) - (6*4 - 6*3x) = 3 Right?
So, let's multiply it all out:
(12 - 3x) - (24 - 18x) = 3
Now let's get rid of the parentheses:
12 - 3x - 24 + 18x = 3, right?
[when you have a '- (something)', that's the same as having a '+ -1(something)', so you remove the parentheses by multiplying everything inside them by '-1' like this: '- (24 - 18x)' becomes '+ (-1*24 - -1*18x)' which becomes '+ (-24 + 18x)' which is the same as '- 24 + 18x'].
And that's the same as:
12 - 24 + 18x - 3x = 3, which becomes 15x - 12 = 3
So, let's get rid of that '-12' by adding 12 to both sides of the equation (If you do the same thing to both sides of the equation it doesn't really change.):
15x - 12 + 12 = 3 + 12 becomes 15x = 15
Now, let's make one side only be 'x', by dividing both sides by 15:
15x/15 = 15/15, which becomes x = 1
Is that right? Let's check by putting that answer into the original equation:
3(4 - 1) - 6(4 - 3) = 3
becomes 3(3) - 6(1) = 3
becomes 9 - 6 = 3
looks good to me!

See - it's just a bunch of simple operations; the equations look hard, but they're not really. Now you should handle the other two with no trouble. right?

Answer 3

You choose who has the best answer and they get points for the status!

(1)
3(4-x)-6(4-3x)=3

Firstly, multiply out the brackets.

12-3x - 24+18x = 3

Collect like terms:

15x-12 = 3

Add 12 to both sides:

15x = 15

So x must be 1 since 15*1=15.

CHECK: Substitute x=1 into the original equation if both sides are the same then we will have found the solution.

3(4-1)-6(4-3(1)) = 9 - 6 = 3 (which the the same as the RHS)

(2)
7(3-2x)-2(8-5x)=x

Multiply out the brackets

21-14x - 16+10x = x

Collect like terms:

5-4x = x

Add 4x to both sides

5x=5

So x=1.

CHECK: 21-14(1) - 16+10(1) = 1

(3)
4(5x-1)+3(1-7x)=x

Multiply out the brackets:

20x-4 + 3-21x = x

Collect like terms:

-x-1 = x

Add x to both sides:

-1 =2x

i.e. 2x = -1

Divide both sides by 2

We have that x =-1/2.

CHECK: 4(5(-1/2)-1)+3(1-7(-1/2)) = 10-4 + 3 -21/2 = 9-10.5 =-1/2. Which is the same as the right hand side.

Answer 4

i'll only explain the first expression as the others will work in the same way.

3(4-x) is just 3 multiplied by 4-x = 12-3x.
-6(4-3x) = -24 + 18x (the same reasoning as the above).

Therefore you have 12 - 3x -24 +18x = 3

Rearrange the equation to get -3x + 18x = 3 - 12 + 24
which is equivalent to 15x = 15
Therefore x = 1

If you are not sure about rearranging the equation and how it works, just keep in mind that you aim to have x on one side of the equation and the other side just a number. From 12 - 3x -24 + 18x = 3, you want to keep -3x + 18x on the left, and therefore you have to take away 12 and -24. This is done by deducting 12 away and adding 24 on both sides of the equation (so both sides are still equal).

Hope that is clear

Answer 5

Well Lil its not so freaky deaky
You have to solve simple
equations of first degree
The generall idea is to get
rid of the parenthesis doing
the multiplications and after
that you seperate the known
from the unknown(those who
carry the x factor).
Then you solve for x dividing
both sides with the number in front of x.
(if it is not zero) and you get one solution.
If it is zero you have either no solution
or an infinite number of solutions and
you can understand this just looking at
the equation
So 3(4-x)-6(4-3x)=3
12x-3x-24+18x=3
12x-3x+18x=3+24
Take care that if a quantity changes
side it changes the sign before him
27x=27
x=27/27
x=1
I leave the rest for you.
Good luck
Καλη τυχη

Answer 6

If I explain the first of these, you should be able to do them all. They are all very similar.

3(4 - x) - 6(4 - 3x) = 3
Multiply each term inside a bracket by the number outside the bracket. When the number outside the bracket is negative (-6), you must change the sign of every term inside the bracket which follows.
12 - 3x - 24 + 18x = 3
Collect x terms together, and collect absolute terms (absolute terms are those which are just numbers.
12 - 24 - 3x + 18x = 3
Simplify by combining absolute terms and combining terms in x:
-12 + 15x = 3
Add 12 to each side, to collect the absolute terms on one side of the equal sign and the x terms on the other.
15x = 15
Divide by 15:
x = 1.

Hope that's enough explanation for you to complete the exercise.

Answer 7

12 - 3x - 24 + 18x = 3
15x = 15
x = 1

21 - 14x -16 + 10x = x
5x = 5
x = 1

20x - 4 + 3 - 21x = x
2x = -1
x = -0.5

Answer 8

3(4-x)-6(4-3x)=3
12-3x-24+18x=3
-12+15x=3
-15= -15x
x=1

Answer 9

That is freaky deaky

Answer 10

cheater copys some one home work