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A is the point (2,-5), B is the point (-1,4). (a) What is the gradient of the line passing through points A and B? (b) Does the point (-100,301) lie on the line passing through points A and B?

(a) let A be (x1,y1) and B be (x2,y2), Gradient = m = (y2-y1)/(x2-x1) m = (4- -5)/(-1-2) = 9/(-3) = -3 Gradient = -3 (b) equation of a straight line line: y = mx + c => y1 = m(x1) + c -5 = -3(2) + c c = -...
HM
Answered by Hallam M. • Maths tutor
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What is the difference between the function of platelets, white blood cells and red blood cells?

They are all components of blood. Platelets are small fragments of cells and help blood to form clots. This stops the body from bleeding when a blood vessel gets damaged. White blood cells destroy microorgan...
TD
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Factorise: x^2+2x-3

think of it in the form of Ax^2 +Bx +C. Most of the GCSE examples will have A as zero so we will ignore the A. To factorise this you need to find what two numbers multiply to make C and adds to make B. In th...
KA
Answered by Katherine A. • Maths tutor
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Explain why the atomic radius of elements decreases as you move across the periodic table from the left to the right

Periodicity:As you move across the row the atomic number increases, ie an additional proton is added for each additional element, this is what makes them different elements rather than isotopes of the same e...
BB
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Explain why cis- alkenes typically have a lower boiling point than trans alkenes.

Define cis and trans alkenes: Carbon to carbon single bonds can freely rotate to give a carbon chain that can take on a number of shapes (this is to do with the overlap of p - orbitals to form pi bonds) howe...
BB
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