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3x + 5y = 1   (eq 1)
2x - 3y = 7    (eq 2)

Step 1 -  2* (eq 1) 

6x + 10y = 2  (eq 3)

Step 2 - 3* (eq 2)

6x - 9y = 21  (eq 4)

First you need write out the balanced chemical equation. You will often be asked about iron(II) ions reacting with maganate(VII) ions or with dichromate ions, therefore it is easiest to learn these two eq...

The table is a cylinder so we'll need to use the equation for this shape: A = πr²h

We're looking for the thickness of the table (which is the height) so let's rearrange this equation to ...

President from 1829 to 1838, Andrew Jackson was the source of much political conflict thanks to a combination of his belligerent personality and his political views and strategy. In some respects other fa...

So we know the formula for the area of a circle: πr² 

So all we need to find is the radius²

Radius = Diameter / 2 (Half the diameter)  

            = 70

R...