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Prove that the square of an odd number is always 1 more than a multiple of 4

(2x-1) 2 = 4x 2 - 4x + 1= 4(x 2 -x)+1The part of the expression which is: 4(x 2 -x) indicates that the value is a multiple of 4. The number 1 is then added which means that the statement 'the square of an od...
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Answered by Gokul P. • Maths tutor
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4y^2 = 256, Find a value for y

y^2 = 256/4 = 64 therefore, y = sqrt(64) = 8
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Answered by Kai P. • Maths tutor
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Solve the simultaneous equations: 2x + y = 12; x - y = 6

We add the two equations together (left-hand sides and right-hand sides separately). By doing this we get: 2x + y + (x - y) = 12 + 6. By rearranging and simplifying: 3x = 18.If we divide both sides by 3 we g...
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Answered by Rebeka D. • Maths tutor
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explain ionic bonding in a giant ionic lattice?

Bonding is about the movement of electrons-electrons are NEGATIVELY charged-the electrons move to allow atoms to become more STABLE by having a full outer shell of electrons-The periodic table is useful to l...
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Answered by Maria A. • Chemistry tutor
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Calculate the relative formula mass of aluminium sulfate, Al2(SO4)3 (2 marks)

As the question is 2 marks, show working to ensure you get a mark even if answer is slightly wrongFrom periodic table you can see that the relative atomic masses are oxygen = 16; aluminium = 27; sulfur = 32(...
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Answered by Amy S. • Chemistry tutor
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