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Solve the simultaneous equations: 3x + y =11; 2x + y = 8

subtract one from the other to eliminate y: 3x+y=11; 2x+y=8 --> x=3 substitute value of x back in and solve for y : 3(3)+y=11; 9+y=11; --> y=2
IH
Answered by Israel H. • Maths tutor
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(a) Expand and simplify (x − 3)(x + 5), ..2 marks.. (b) Solve x^2 + 8x − 9 = 0 ..3 marks..

(a) Remember: Multiply each term in the left bracket by every term in the right bracket.(x-3)(x+5) = x 2 + 5x - 3x -15.Collecting all of the like terms:= x 2 + 2x -15. (b) Solve x 2 + 8x − 9 = 0Remember to p...
JW
Answered by Jack W. • Maths tutor
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What is the difference between simple diffusion and active transport?

Simple diffusion is the movement of a molecules from an area of high concentration to an area of low concentration across a semipermeable membrane. Diffusion happens in liquids and gases as their particles m...
SK
Answered by Simi K. • Biology tutor
19062 Views

What techniques would you use to separate: 1) different colour inks from black ink. 2) ethanol from ethanol and water 3) salt from water

You would use chromatography, the different colours have different affinities depending on the solvent you use. So different colours will travel longer than other on your chromatogram (support).2) You would ...
Answered by • Chemistry tutor
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Are you able to list for me: two examples of a hardwood, and two examples of a softwood?

Hardwoods: oak, mahogany, maple, ash, birch, etc. Softwoods: pine, spruce, cedar, fir, etc. Disallow any manufactured boards, e.g. plywood, MDF, etc.
BF
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