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The point P(-3,9) belongs to a line intercepting the origin. Find the equation of the line.

We are told that the line passes through the origin O (0,0) and the point P (-3,9). First we need to find the gradient of the line m; this is given by m = (change in y)/(change in x), hence m = (9-0)/(-3-0) ...
VB
Answered by Valeria B. • Maths tutor
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Solve algebraically the simultaneous equations: x^2 + y^2 = 25 and y - 3x = 13

Firstly we should look at the question and notice that the two possible methods are substitution or elimination. We should then notice that since one equation is a quadratic and the other linear, then the el...
AS
Answered by Aviv S. • Maths tutor
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Polyester is a common polymer used in clothing. State the name of the chemical reaction used to form polyester by reaction of ethanedioic acid and ethane-1,2-diol. Give the name of the molecule which is lost upon condensation of these two molecules.

Name of reaction is condensation polymerisation.Water is lost upon condensation of ethanedioic acid and ethane-1,2-diol (will draw this out on the whiteboard).
MW
Answered by Melissa W. • Chemistry tutor
4453 Views

Vous décrivez là où vous habitez pour votre blog. Décrivez ...

In order to gain 10 out of 10 for the "content" side of this question, there are certain things a student must do. I would say the easiest way to gain a marker's confidence is responding to all fou...
SG
Answered by Saoirse G. • French tutor
3189 Views

There are 5 red balls and 7 green balls in a bag. A ball is taken from the bag at random and not replaced. Then a second ball is taken from the bag. What is the probability that the 2 balls are the same colour?

Initially, there are 12 balls in the bag. Therefore the chance of the first ball being red is 5/12 and green is 7/12. The probabilities of the second ball are dependent on the first ball, as it is removed fr...
SL
Answered by Stanley L. • Maths tutor
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