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Solve the following simultaneous equations: x^2 + y^2 = 5, y - 3x = 1.

Begin by rearranging equation 2 so that it is in the form y = ... Substitute this into equation 1 Expand the brackets and simplify the equation so that it is in the form Ax^2 + Bx + C = 0 Factorise this quad...
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Answered by Daniel O. • Maths tutor
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What is a social class?

Social class is a way of categorising people according to certain qualities they may have, or conditions in their life. In the United Kingdom this can be things like your parents' jobs, what kind of educatio...
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Answered by Ciara C. • Sociology tutor
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décrivez vos vacances idéales

Un jour j'aimerais beaucoup visiter L'Egypte. Depuis avoir vu une exposition sur Tutankhamun, un des pharaon le plus puissant à exister, je rêve d'aller visiter les pyramides pittoresque et voir tout les nom...
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Answered by Gabrielle W. • French tutor
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A student titrated a solution of 25 cm3 of NaOH of concentration 0.1 mol/dm3 with H2SO4. She achieved four results; 25.8 cm3, 26.15 cm3, 26.25 cm3 and 26.45 cm3. Calculate the concentration of H2SO4 using concordant titres.

H 2 SO 4 + 2NaOH → Na 2 SO 4 + 2H 2 O Concordant titres: 26.15 cm 3 and 26.25 cm 3 Mean titre: (26.15+26.25)/2= 26.2 cm 3 /1000= 0.0262 dm 3 moles of NaOH: (25/1000)*0.1= 0.0025 mol Ratio of H 2 SO 4 : NaOH=...
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Answered by Shimin S. • Chemistry tutor
4303 Views

Solve n^2+n-90=0 to find the value of n?

Using the quadratic formula with a calculator a=1 b=1 c=-90 answers are n=-10 and n=9Factorising (n-9)(n+10)=0 answers are n=-10 and n=9
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Answered by Asher L. • Maths tutor
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