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How do I solve a quadratic equation like x^2 - 2x - 35 = 0 without using a calculator?

If possible, you should try to factorise a quadratic. To do this, look a the factors of the constant, in this case -35. 35 is clearly divisible by 5, and 35 / 5 = 7, so 5 and 7 are one pair of factors. These...
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Answered by Alfie H. • Maths tutor
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How do I expand (x - 4)(2x + 3y)^2 ?

To start off, to make things clearer we can write the expression as:(x - 4)(2x + 3y)(2x + 3y)Now focus on just two of the brackets, say (2x + 3y)(2x + 3y). To expand this, we need to do the following four mu...
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Answered by Hector M. • Maths tutor
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Calculate the length of PR. Give your answer correct to 3 significant figures (Diagram displayed on whiteboard)

In order to work out the unknown length of the triangle side PR, we first must identify which trigonometry equation to use. The digram gives us three values- 1 side and 2 angles. We know the hypotenuse (the ...
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Answered by Ali A. • Maths tutor
14182 Views

The value of a car depreciates by 35% each year. At the end of 2007 it was £5460. Work out the value of the car at the end of 2006.

-This question wants us to work backwards.Let N be the value of the car in the year 2006. Find the multiplier . 1-0.35 = 0.65. Hence N * (0.65) = £5460. Rearrange for N. N = £8400
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Answered by Rithvik G. • Maths tutor
11337 Views

The second and fifth terms of a geometric series are 750 and -6 respectively. Find: (1) the common ratio; (2) the first term of the series; (3) the sum to infinity of the series

x n = ar (n-1) (1) x 2 = 750 = ar 1 (2) x 5 = -6 = ar 4 divide second equation by first-6/750 = r 3 r 3 = -0.008r= -0.2Insert into first equation.750 = a * -0.2a = -3750Sum to infinite series = a(1/(1-r))(in...
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Answered by Henry P. • Maths tutor
6687 Views