Eric Nicholas K's answer to Wesley's Secondary 4 E Maths Singapore question.
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Something like this will be good.
Sorry for the messiness, I got careless at first which led to the rejection of both my answers.
The reason why "18/19" is cancelled in the question is that the quadratic equation (39x - x^2)/380 = 18/19 will soon reduce to the equation x^2 - 39x + 360 = 0 with solutions x = 24 and x = 15, both of which would have to be rejected since 15 blue pens + 6 red pens = 21 pens which already exceed the 20 pen count.
Sorry for the messiness, I got careless at first which led to the rejection of both my answers.
The reason why "18/19" is cancelled in the question is that the quadratic equation (39x - x^2)/380 = 18/19 will soon reduce to the equation x^2 - 39x + 360 = 0 with solutions x = 24 and x = 15, both of which would have to be rejected since 15 blue pens + 6 red pens = 21 pens which already exceed the 20 pen count.
Date Posted:
4 years ago
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