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Given that y = 5x^2 - 4/(x^3), x not equal to 0, find dy/dx.

y = 5x 2 - 4/x 3 1/x can be written as x -1 , which means our equation can also be written as y = 5x 2 - 4x -3 . dy/dx means that we need to differentiate y in terms of x. To differentiate an equation, we ne...
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Answered by Nick12 L. Maths tutor
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Solve the simultaneous equations (with a calculator)

x^2 + y^2 = 9 x + y = 2 1) Firstly look at the second equation which is the simplest and think how you can rearrange it to fit into the first equation: x + y = 2 can be rearranged to y = 2-x 2) y = 2-x can t...
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Answered by Emily G. Maths tutor
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Solve these simultaneous equations. 5x + 2y = 20 and x + 4y = 13.

(1) 5x + 2y = 20(2) x + 4y = 13Step 1: Eliminate x or y. We do this but making either the x or y terms the same, in this example, I will make the y terms the same, by multiplying the first equation by 2.(1) ...
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Answered by Andrew B. Maths tutor
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Solve 3(x+4) = 18

The first step would be to multiply out the bracket. So, using this example we would times each item inside the bracket by 3. As a result we would get: 3x + 12 = 18 Then we would need to move the 'x' value t...
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Answered by Alexandra B. Maths tutor
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How do I rationalise the denominator of a fraction?

I am going to assume you know what an irrational number is, given that that should have been taught right at the beginning the topic of surds. When I talk about a “rational” number, here I mean “whole number...
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Answered by Andrew D. Maths tutor
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