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Solve the simultaneous equation: 2x + y = 18, x - y = 6

First, we simply label the two equations as 'Equation 1' and 'Equation 2' respectively. So we have: Equation 1: 2x + y = 18and Equation 2: x - y = 6. In simultaneous equations, there are two variables: x and...
HM
Answered by Harry M. • Maths tutor
4795 Views

25 cm3 of NaOH was titrated with 0.050 mol dm-3 HCl. NaOH + HCl --> NaCl + H2O. 21.5 cm3 HCl neutralised 25 cm3 NaOH. Concentration of NaOH in mol dm-3?

21.5 cm 3 / 1000 = 0.0215 dm 3 of HCl. n = cv so (0.050) x (0.0215) = 0.001075 mols of HCl. NaOH + HCl --> NaCl + H 2 O so there is a 1:1 ratio of reactants to products. Therefore there are 0.001075 mols ...
AS
Answered by Arran S. • Chemistry tutor
3532 Views

Why is space important in Middleton and Rowley's The Changeling?

First of all, it's definitely safe to say that space is one of the play's key themes. We see it in lots of different ways - but in the broadest sense, you should notice how the play moves from a wide open sp...
DE
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What is history?

One of the first recorded attempts to define narrative, and therefore begin to understand its associations with history, was Aristotle in Poetics [1] , in which he alludes to the idea of a “plot-based”[2] th...
SW
Answered by Samuel W. • History tutor
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How do I expand a bracket to a negative power if it doesn't start with a 1.

Okay so consider (2 + x)^-1, we can only do the expansion we know if the bracket starts with a 1, to fix this we can factor a 2 out of the bracket so that it becomes (2(1 + x/2))^-1. Then by our rules of pow...
SM
Answered by Shaun M. • Maths tutor
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