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Solve the simultaneous equation, 3x + y = 8 and x + 3y = 12, to find a value for x and y.

Re arrange one of the equation to get a single variant answer. So, x = 12 - 3y. Substitute this into the other equation, so 3 (12-3y) + y = 8. Expand this equation to form 36 - 9y + y = 8. Collect the y t...

Answered by Grace R. • Maths tutor

6786 Views

Show that (x + 4)(x + 5)(x + 6) can be written in the form ax3 + bx2 + cx + d where a, b, c and d are positive integers.

=(x+4)(x²+6x+5x+30)=(x+4)(x²+11x+30)=x³+11x²+30x+4x²+44x+120=x³+15x²+74x+120

Answered by Jiawen Z. • Maths tutor

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Explain why an extensive network of capillaries and ventilation of the lungs helps to maximise the effectiveness of gas exchange.

The capillaries deliver blood that has high carbon dioxide levels and low oxygen levels and take away blood that has high oxygen levels and low carbon dioxide levels. This means there is always a concentr...

Answered by Annabel C. • Biology tutor

6987 Views

Compare and contrast the structure and bonding of diamond and graphite.

1 mark each for each of these points:similarities:only contain carbon atomsatoms covalently bonded to each otherlattice structuredifferences:diamond has four covalent bonds and graphite has threediamond h...

Answered by Annabel C. • Chemistry tutor

4738 Views

Explain the meaning of ratio decidendi in the doctrine of precedent. Illustrate your answer by reference to a relevant civil law or criminal law case.

The doctrine of precedent stipulates that, unless they clash with statute, decisions of the highest court with respect to a specific legal matter, are bound upon lower courts, as well as the courts in whi...

Answered by Manos D. • Law tutor

6650 Views