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Solve this pair of simultaneous equations: 3x + 2y = 4 and 2x + y = 3

2x + y = 3 therefore y = 3 - 2x Substitute y = 3 - 2x in to the first equation: 3x + 2(3 - 2x) = 4 3x + 6 - 4x = 4 -x = -2 therefore x = 2 Substitute x = 2 in to either equation: 2(2) + y = 3 4 + y = 3 y = -1
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Answered by Tim C. • Maths tutor
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A solution of ethanoic acid in water has a concentration of 3 g/dm^3. Given that the pKa of ethanoic acid is 4.76, calculate the pH of this solution.

Key facts to be noted by student: Molar mass of ethanoic acid = 60 g/mol. pK a = -log(K a ) pH =-log([H + ]) Concentration of acid solution = 3/60 = 0.05 moldm - 3 k a = [H + ] 2 / [CH 3 COOH] therefore [H +...
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Answered by Tim C. • Chemistry tutor
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mRNA is used in translation to make polypeptides. Describe the process of how mRNA (Messenger RNA) is produced in the Nucleus.

Helicase unwinds the DNA double helix strucutre This is done by breaking the hydrogen bonds Only one strand is then used as a template RNA nucleotides bond/ attract to exposed bases This is according with co...
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Answered by Sophia B. • Biology tutor
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Solve x² - 3x - 2 = 0

To complete the square for the equation ax² + bx + c = 0 there are three steps.. 1. In order to complete the square, we need to take the first two parts of the quadtratic equation, and put them in the form o...
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Answered by Natalia M. • Maths tutor
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Discuss the theme of 'anguish' in James Fenton's poem, 'In Paris With You'

In James Fenton's poem, the speaker expresses anguish at the romantic situation between himself and his lover through his use of coined terms. The speaker suggets his frustration at the unreciprocated love b...
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Answered by Charlotte G. • English tutor
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