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Maths Factorisation Question

randomlad727 · 2015-11-01 16:39:01

Hello. Just wondering if anybody could help me factorise the equation: a^2 +2ab+10b^2=0 (the ^ meaning to the power of) Thanks in advance for any help.

01-11-2015 5:39pm

#1

randomlad727

Registered Users Posts: 29 ✭

Join Date: August 2015

Posts: 27

Hello. Just wondering if anybody could help me factorise the equation: a^2 +2ab+10b^2=0 (the ^ meaning to the power of)

Thanks in advance for any help.

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Comments

#2 01-11-2015 5:45pm

PinkLemonade

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Are you sure on the signs?

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#3 01-11-2015 5:53pm

randomlad727

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Join Date: August 2015

Posts: 27

Actually coming to think of it I may be going wrong earlier in the question. It is an abstract inequality question.
The equation starts off as : a^2 > -2b(a+5b) . I assumed you would multiply out the brackets and then bring everything to one side but maybe this is where I am going wrong. (> supposed to mean greater than or equal too but I dont know how to get the full sign on the keyboard)

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#4 01-11-2015 7:35pm

skippy1977

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You were on the right track. Trick is to split the 10 up into 9+1...that way you can complete a square with the other terms (which must be positive, or 0) and the 9b^2 is also positive (or 0)

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#5 01-11-2015 9:33pm

randomlad727

Registered Users Posts: 29 ✭

Join Date: August 2015

Posts: 27

Great! Thank you for your help! Much appreciated!

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