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Solution: x=4. This can be shown by factorisation or applying the quadratic formula.

Most GCSE papers are split between a number of short answer questions worth a few marks and then one or two longer 'essay-style' questions which are worth considerably more. The key thing to focus on is e...

Sodium chloride is an ionic compound. It is made of sodium ions which have lost an electron to become positively charged (Na+) and chloride ions which have gained an electron to become negatively charged ...

Pythagoras theorem works to find out an unknown side length of a right angles triangle (RAT) knowing the other two lengths. A RAT has 3 sides called a hypotenuse (longest side), and two smaller sides. We ...

An exothermic reaction is one where the products have less energy than the starting reactants.  This means the reaction must give out energy, usually in the form of heat or sound.  As a result of this, H ...