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How to factorise 6x^2-11x-10?

Firstly, when we need to factorise an expression like ax 2 + bx + c, we should find two numbers m and n such that mn = ac and m+n = b. In this question, a = 6, b = -11, c = -10. So mn = -60 and m+n = -11. Le...
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Answered by Yunxi S. • Maths tutor
18816 Views

Show that (x+2)(x+3)(x+4) can be written in the form of ax^3+bx^2+cx+d where a, b, c and d are positive integers.

This is a 'show that' question which means that you need to prove that something is true. This question wants you to rewrite (x+2)(x+3)(x+4) into the form of ax^3+bx^2+cx+d. To do this, we have to expand the...
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Answered by Alicia H. • Maths tutor
8643 Views

In a bag of balls, 3 are red, 2 are blue and 5 are green. Two balls are selected from the bag. Calculate the probability that both are green.

Answer:2/9On the first pick of the bag, there are 10 balls in total. Out of these balls, 5 are green. Therefore the probability of picking a green ball will be 5/10 or 1/2. On the second pick of the bag, the...
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Answered by Charlie H. • Maths tutor
11304 Views

Using the principle of the conservation of energy, calculate the maximum speed of a ball of 5.0kg that has been dropped from a height of 20m. (Given that the gravitational field strength is equal to 9.8N/kg)

Answer: 20ms -1 The gravitational potential energy before the ball is dropped is equal to mgh. This gives the ball a maximum gravitational potential energy of 5.0kg * 9.8N/kg 20m which is equal to 980 J. At ...
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Answered by Charlie H. • Physics tutor
4116 Views

Given that a light ray enters a glass prism at angle of 50 degrees from the normal and is refracted to an angle of 30 degrees from the normal, calculate the speed of light in glass.

Answer: 1.96 10 8 ms -1 .Snell's law tells us that n 1 sin(x 1 )= n 2 sin(x 2 ) where x is the angle of a light ray from the normal. Air can be assumed to have a refractive index of 1. Therefore, sin(x 1 ) =...
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Answered by Charlie H. • Physics tutor
3811 Views