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Do you recognise the form:
?

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yes

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its for a straight line

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Can you rearrange into that form?

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y=8x+-4?

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Not quite, be careful with the signs

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Have another go

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What I wrote it like this:

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then*

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Which term do you need to move to the right?

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the would you divide?

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Remember we are trying to make look like

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8x

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Yes, we need to from both sides. What do you think it will look like then?

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y+8x-8x=-4 -8x ?

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Yes, which simplifies to what?

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-12?

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Okay we have . What terms do you think will cancel each other out?

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8x

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-8x

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Brilliant, so can you now simplify:

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You need 2 terms to cancel. So far we have , what will cancel that?

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would you divide -4 from -8x ?

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We can do this entirely with addition and subtraction. We know that and cancel, so what do we do with those terms in:

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subtract?

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Write out the whole equation

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I think you've got it

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y=-8x-(-4) ?

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Almost!

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which is the same as

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Rearranging can be hard at first, but I think another time we need to go through the rules. Once you're familiar with those it will be much easier.

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Do you know what the "intercepts" are?

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x and y coordinates

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x and y coordinates could be anything, Where would we find the intercepts on a graph?

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wouldn't you replace the values of x and y

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like y=-4-8(0) then simplify y=-4

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Yes!

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so wouldn't y intercept at -4

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Exactly, we also know that in the form that C will always be the intercept

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Okay, what about the x intercept?

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Remember the original form

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8

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Try and break it down into stages

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how do we rearrange that to find ?

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y=x/8?

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We are looking at the equation . I have replace with so we can find the x intercept. Just like when you set to in the last bit.

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We need to get it so that is on his own. At the moment there is an there. How can we move the to the left side?

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from both sides?

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0/-4?

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8 is a little different from earlier as it multiplying

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subtract

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Okay think of it a different way.

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We could divide both sides by 8

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to give

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8x/8x cancel out

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Yes,

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so what is the value of the x intercept?

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, or more simply

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So we could write , or more simply

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Sorry

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4

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1

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Not quite, if we make it look like this, it might be clearer

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would you divide -4/8 ?

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We could also say it in words. x equals minus 4 divided by 8.

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So lets recap

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Yes

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-0.5.

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so what value is minus 4 divided by 8?

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the intercept is , and the intercept is

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Are you comfortable drawing that?

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not really i never graphed -0.5 or other like it, how would you?

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Have you got some squared paper?

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yes

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Draw a set of axes in the middle of the page. What range should you put on the axes to make sure we get both of the intercepts in?

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bh104, I must go now. You can see an example of the graph here: http://bit.ly/I8kcFE . Look at the X and Y axes and see where the lines crosses them.

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point o -4

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ok thank you

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My pleasure. Hope it helped

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Yes thank you

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If you have any more questions then post them up

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