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Factorise a^2 + a - 30

This is a quadratic equation in the form ax 2 +bx+c. As the three terms don't have a common factor we cannot factorise this into one bracket, instead we will factorise it into two. In order to do this we mus...
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Answered by Isabella G. • Maths tutor
5364 Views

why does graphene conduct electricity?

usually covalent structures cannot conduct electricity but graphene is one of the exceptions and this is due to its structure and bonding. It is a giant covalent 2D molecule, hexagonal in shape with 3 covale...
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Factorise x^2+3x-4

Answer is:(x-1)(x+4)
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Answered by Tahmina A. • Maths tutor
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State the reagents and conditions for the formation of an aldehyde, starting from a primary-alcohol.

Answer: Heat with acidified potassium dichromate (IV), distilling off the aldehyde as it forms. Explanation: To form an aldehyde from an alcohol the alcohol group must be oxidised. To do this we use potassiu...
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Answered by Tom O. • Chemistry tutor
6113 Views

Which verbs use etre and which use avoir in the past tense, and why?

The past tense is constructed in 2 parts: 1) the auxiliary 'avoir' or 'être' is conjugated in the present + 2) the past participle of the verb. The majority of verbs use avoir in the past tense (e.g. j'ai ma...
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Answered by Flick W. • French tutor
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