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Solve the following simultaneous equations: x^2-y^2=9, x - y = 1

We first notice we have a linear and non linear equation. The simplest method to solve is to substitute the linear equation into the non linear equation and then solve for one of the unknowns. Then substitut...
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Answered by Shantu H. • Maths tutor
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Derive an expression for the time taken, (t) for a test mass to fall to the ground from a height (h) in a uniform gravitational field (g = 9.81 ms^-2)

We first build an intuition for exactly what acceleration is and what we expect to happen. In the uniform gravitational field approximation, we assume h to be much less than the radius of the Earth. Therefor...
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Answered by Charlie B. • Physics tutor
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How do you know whether to use the preterite tense or the imperfect tense?

That is a very good question, as both describe actions of the past. We use the preterite tense when we talk about actions which are seen as being completed in the past, notably one-off events. For example, y...
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Answered by Zoe S. • Spanish tutor
2828 Views

Make s the subject of the equation: 4st + 8 = 5r

To begin this question, we want to isolate the term containing the s, i.e. have the term containing the s by itself on one side of the equality. We do this by subtracting 8 from both sides. 4st = 5r - 8 To m...
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Answered by Sophie W. • Maths tutor
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A rectangle has an area of 20cm^2. Its length and width are each enlarged by scale factor 3. What is the area of the enlarged rectangle?

For questions regarding enlargements of shapes, it's sometimes easier to consider one dimension at a time. So for this example, let's first consider what the area of the rectangle would be if we just enlarge...
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Answered by Sophie W. • Maths tutor
10059 Views