A couple of points before we move on to the next topic.
On the question about the buffet meal, everyone managed to get the two expressions representing the old price per person (160/x) and the new price per person (160/(x+4)).
The tricky part is putting the equation together.
To do this you need to say that the old price minus the new price is 2 euro (as they tell you that the new price is cheaper).
(160/x) - (160/(x+4)) = 2
And solve.
[You could also work it out by saying the new price + 2 euro = old price]
A few people made worrying mistakes on BEMDAS.
In ....
3(-1)²
it is the -1 that gets squared, not the 3, so the answer is 3(1) = 3With the double inequality, you can solve it all in one go but it is easier to follow if you split it into two inequalities and solve them separately.
Most of you managed the long division nicely.
In the equation with algebraic fractions many of you made it very complicated, looking for a large common multiple ... instead of just multiplying both sides of the equation by the smallest number that would make all the fractions disappear.
Finally, many of you managed to express 3/(2x-1) - 2/(3x+1) as a single fraction, but completely missed the point of verifying your answer by setting x = 1.
If you just sub x=1 into your answer you are not verifying (i.e. proving) anything.
The point is that if you replace x with 1 in the above expression you get 3/(2-1) - 2/(3+1) = 3 - 1/2 = 2.5
and if you replace x with 1 in the answer you got for the single fraction
(should be (5x + 5)/(2x-1)(3x+1), you'll get (5+5)/(2-1)(3+1) = 10/4 = 2.5
You verify that you haven't changed the value of the expression by subbing x=1 into the original version as you were given and your new improved version of the expression and getting the same answer in both.
Note that you can do this verification to check that you haven't made a mistake anytime you are asked to simplify an expression, write as a single fraction etc.
Tomorrow we will start on arithmetic.
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