Lecture 1

Teacher : We can find the value of a by using the following equation, a = b+c. a would be a valid answer if a = 0 !

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Teacher : a = b-c, if b = 0, c = 1,
Teacher : we would get a = -1, so the answer for a is not valid.
Student : but u mention earlier that a = b+c .
Teacher : did i? u saw the wrong equation la..

**teacher quickly refer back to the text book and found that it's true that a = b+c**

Teacher : ok, so a = b+c,
Teacher : we obtain the value of a = -1 with the equation a = b-c.
Student : u just mention that a = b+c, but why u r using a = b-c to solve the question???
Teacher : because a=b-c !!
Student : huh????? how come different from what u mention earlier?
Teacher : just follow la a = b-c .
Teacher : aiyoh, a = b-c ...... a=-1 and a =b+c ......a=1
Teacher : both the value of a also not equals to zero!! so what is the difference? value of a is still not valid.
Student : ...............