Melody

This is a reapeating question but always a good one. :)

Yes I like it too :)

It is undefined.  You cannot divide by 0

ok there is a lot of confusion here so I will see if I can help to straighten it out for it is quite important.

Firstly  7*7=49     AND    (-7)*(-7)=49

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Now if the question is  $$\sqrt{49}$$   then the answer is 7     (Just 7 NOT -7)  

This is because if the square root is written into the original question ONLY the positive answer counts.  That is a convention. 

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However,  if the question is   

$$\\x^2=49 \qquad find\quad x \\\\
$That is different because the square root is not written into the original question.$\\\\
x=\pm\sqrt{47}=\pm7$$

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Please, if you want to ask questions do so because this is important.

$$\frac{\sqrt{84}}{2}}\times\sqrt3\\\\
=\frac{\sqrt{4\times 21}}{2}\times\sqrt3\\\\
=\frac{\sqrt{4}\times \sqrt{21}}{2}\times\sqrt3\\\\
=\frac{2\times \sqrt{21}}{2}\times\sqrt3\\\\
=\sqrt{21}\times\sqrt3\\\\
=\sqrt{7}\times\sqrt3 \sqrt3\\\\
=3\sqrt{7}\\\\$$

4.992

Any number divided by 1 stays the same. :)

Good one Alan :)

$$Gradient = \frac{rise} {run}=\frac{change\;in\;y}{change\;in\;x}=\frac{7-2}{6-4}=\frac{5}{2}$$