Math Is Fun Forum

sweetangel786

Member

Registered: 2006-03-18

Posts: 20

Urgent Need Of Help!! Please Please Please......

hi, i know i have asked many questions, i have my mock exam 2morro and i still don't understand on equations i know other things in  maths but i have problems on learning this..
i don't understand :
how to work out equations, i have asked this question b4 few dayz ago, but i iam stil very confused about it.
understanding this will really help me if anybody can...
it will help me on my mock exam 2morro.. please can u help me to understand equations and algebra ....
thanks u all very much if u can help me..... it's very importatnt i learn it and understand it by 2day... in the evening..
thank u.. sweetangel786.....   

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practise makes people perfect, but nobody's perfect so why practise...

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,418

Re: Urgent Need Of Help!! Please Please Please......

sweetangel786, I shall try to explain to you about equations.
A mathematical equation is putting two like (or equal or same) together and showing they are equal.

For example,
Q1) Find x if 8x + 12 = 60.
It is given that 8x+12=60.
We can take away 12 from both sides,
Therefore, 8x=60-12=48.
If 8 pens were to cost $48, you knoe the cost of each is 48/8=6.
Similarly, here x=6 since 8x=48.

Q2. If 3x + 2y = 16 and 2x-y=1, find x and y.
(These are called simultaneous equations of two variables)

Lets take 3x + 2y = 16 as equation (1)
and         2x - y = 1 as equation (2).

We have to first eliminate one variable, that is either x or y.
In order to do that, we have to make x or y equal in both the equations. Lets eleminate y here.
                         3x + 2y = 16 ... equation (1)
equation (2) x 2 : 4x - 2y = 2

Adding equations (1) and (2)

3x+4x +2y+-2y = 16-2.
7x = 14,
x=2.
Now put x=2 in equation(1)
3x + 2y = 16
3(2) + 2y = 16
6 + 2y = 16
2y = 16-6 = 10.
Therefore, y = 10/2 = 5.
Therefore, the solution is x=2, y=5.

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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