Maths

• Created by: rutwij_12
• Created on: 05-02-16 17:46

Algebraic Expressions-Expanding brackets,factorisi

When trying to simplify or factorise any equation you should copy the sum down and work your way downwards.

Firstly, you should try to make sure the variable is on its own. If the variable has a gradient, you can include that in the equation and take it off at the end of the equation.

An example of an equation is:

Work out the value of y:

3y+6=30

Firstly you put the 6 on the other side, but it has to turn into a negative 6.

3y=30-6

3y=24

Now you take the 3 onto the other side but it has to turn into a divisor.

y=24/3

y=8

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Adding, Subtracting, Multiplying and Dividing deci

A few tips to remember when dealing with decimals:

When adding or subtracting decimals make sure the decimals are in line:

eg- 4.50+

5.66                                    An extra 0 was added to make sure 4.5 matches to 5.66

When multiplying, make sure when calculating the final answer, the decimal is in the amount of spaces both of the numbers are:

eg- 5.1*2=not 102,1002 but the answer is 10.2

When dividing decimals make sure you first convert the numbers to whole before dividing-

23.4 and 46.8

so when you  *10

you will get 234 and 468

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Interior angles in a polygon

For these type of questions you will have to know how much degrees are in a shape and how to calculate this.

Some important equations/formulas are...

a straight line=180˚

a circle=360˚

To work out how many degrees are in a shape, the formula is:

180(n-2)                                    n is the number of sides

An example is :  a triangle

so

180*(3-2)

so 180*1=180

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The gradient is the number that comes before the variable.These are a few examples:

y=3x+5              The numbers that are highlighted are the gradients

x=2y-6

For these 2 equations can you work out the gradient?

y=2x+1

x=4y-3

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4 puɐ 2 sı ɹəʍsuɐ əɥʇ.

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Co-ordinates

When writing co-ordinates remember to is to put brackets around all your points as this shows that the pointis a co-ordinate and not a random number...

10,11 what? 10 to 11 eggs, a bowling party at 10 to 11???

so when you put (10,11) everyone knows you are talking about a grid.

Another thing to remember while writing co-ordinates is to make sure you start with the x axis first and then the y axis.

if you want any point which is on the line x=y+1 then you would write (10,11) not (11,10)

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Interchanging between fractions, decimals and perc

This is an example of how to interchange between fractions, decimals and percentages:

10% is 10/100 as percent means out of a hundred.

To change this into a decimal, all you need to do is to divide your percentage by 100, so in this case, 10% would be...

10/100 = 0.10

=0.1

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