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secondary 4 | A Maths
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Please help with Q4(a) and Q6! Thnks in advanceee

Date Posted: 4 years ago
Views: 257

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Kuwabara Tsusha
Kuwabara Tsusha's answer
4 answers (Tutor Details)
1st
Boy Mow Chau
Boy Mow Chau
4 years ago
answer for Q4(a) missing some values due to improper method.

answers for Q6 do not satisfy original equation.

please refer alternative solution posted.
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Boy Mow Chau
Boy Mow Chau's answer
316 answers (Tutor Details)
(1) when solving equations, can cancel away constants, but do not cancel away any terms with unknowns, otherwise you will "lose" some of your possible answers.

(2) after obtaining final answers, best to check answers by putting EACH answer back into the original equation and make sure equation is satisfied.
Boy Mow Chau
Boy Mow Chau
4 years ago
regarding point (1) mentioned above, lets re-phrase it slightly.

if you have an equation with ...
(something PLUS x) on one side, and
(something else PLUS x) on the other side,
you can subtract x from both sides.

however, if you have an equation with ...
(something MULTIPLY x) on one side, and
(something else MULTIPLY x) on the other side,
you should not divide by x on the two sides and cancel.
it has got to do with the possibility that x may be 0, and division by 0 is not allowed.