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Solve x² ≥ | 5x - 6 | (Question from AQA Core 3 June 2016)

To solve this question we can break it down in to a multiple small stages. The first thing to tackle is the use of modulus around 5x - 6. This effectively means we have two equations to solve: EQ1: x² ≥ 5x -...
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Answered by James H. • Maths tutor
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Solve the simultaneous equations (1) x + 3y = 7 and (2) 2x + y = 4

It's impossible to solve an equation with two unknowns (x and y) so we must find a way to get rid of either x or y before solving an equation. Using substitution rearrange the equation 1 so x is the only ter...
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Answered by Simon S. • Maths tutor
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(i) What property does Magnesium Oxide have that makes it useful to create heat-resistant bricks to line furnaces? (ii) Explain why H2S exists as a gas and H2O exists as a liquid (at r.t.p).

(i) Magnesium oxide is an ionic compound meaning the elements reside in a lattice held together by very strong electrostatic forces of attraction between their oppositely charged ions. Since bonds are broken...
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Answered by Shahaab N. • Chemistry tutor
17896 Views

How can we calculate product yield using reactants and reaction stoichiometry?

If we know the chemistry for a reaction we only need to know quantities from one of our reactants to calculate a product yield. For instance, in a reaction to make hydrogen peroxide, we can calculate the mas...
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Answered by Joshua P. • Chemistry tutor
3142 Views

Why don't Hydrocarbons and Water Molecules mix, and why might an emulsifier fix this?

Hydrocarbons are long chained, non-polar molecules of Carbon and Hydrogen. As the chain length increases the boiling point of oil increases and the intermolecular forces get stronger. At smaller chain length...
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Answered by Joshua P. • Chemistry tutor
7890 Views