Chris -power
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Hi everyone.

I am looking for someone to explain this problem in a very ‘simple simon’ manner.
Multiple 3x + 2y by x - y

Firstly I have added the X’s together to give myself 3x squared + 2y. But my book without any explanation then shows me

3xsquared + 2y squared 😕

Any help will be appreciated
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ghostwalker
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(Original post by Chris -power)
Hi everyone.

I am looking for someone to explain this problem in a very ‘simple simon’ manner.
Multiple 3x + 2y by x - y

Firstly I have added the X’s together to give myself 3x squared + 2y. But my book without any explanation then shows me

3xsquared + 2y squared 😕

Any help will be appreciated
3x^2+2y^2 is not the correct final answer.

From (3x+2y)(x-y), we can split either bracket - I'll choose the second - to get:

(3x+2y)x - (3x+2y)y

Note the minus sign, since it was -y.

=(3x^2 +2xy) -(3xy + 2y^2)

=3x^2 +2xy - 3xy - 2y^2

And tidy up

=3x^2 - xy - 2y^2
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Chris -power
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Size:  500.0 KBHi thanks for you’re reply. Maybe if I had of been a little clearer from the start this would of helped more.

This is the example in question. I am trying understand this but having no real luck of having it translated into something that I can understand. (Simple terms)

Thank you for you’re help
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gurungg48
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Hi
Please check my attachment. Hope thats helpful




(Original post by Chris -power)
Hi everyone.

I am looking for someone to explain this problem in a very ‘simple simon’ manner.
Multiple 3x + 2y by x - y

Firstly I have added the X’s together to give myself 3x squared + 2y. But my book without any explanation then shows me

3xsquared + 2y squared 😕

Any help will be appreciated
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ghostwalker
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(Original post by Chris -power)
Hi everyone.

I am looking for someone to explain this problem in a very ‘simple simon’ manner.
Multiple 3x + 2y by x - y

Firstly I have added the X’s together to give myself 3x squared + 2y. But my book without any explanation then shows me

3xsquared + 2y squared 😕

Any help will be appreciated

Well I can't see any "3xsquared + 2y squared" in that.

In the first part of the question.
3x+2y is firstly multiplied by x, giving one line.
Then 3x+2y is multiplied by -y, giving a second line (lining up corresponding terms together).

Then the two new lines are added together.
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bevkellysherry
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Very belated but I was just trying to find out what level of maths is needed for the HNC in electrical engineering as I have just been asked to help someone and I only teach up to GCSE. To answer your task, if you set them out in a two way table with 3x and 2y at the top and x and -y down the side you then multiply each part together. 3x x x = 3x squared, x x 2y = 2xy (both top layer) then -y x 3x = -3xy and -y x 2y =-2y squared (both bottom layer). You then add all the results together to give you 3x squared - xy - 2y. squared. The 2xy - 3xy = -xy. I hope you have completed your course successfully!
Last edited by bevkellysherry; 1 week ago
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