Question

A market trader asks ₦2 500:00 for some cloth. A woman offer ₦1 200:00. After bargaining,
they agree a price half-way between the two starting prices. (a) How much does the woman pay?
(b) What discount did she get by bargaining?

Answer 1

Answer:

The denominator cannot be zero so

=> x is not equal to 4 or - 6……..(0)

Now for a fraction to be - ve either numerator or denominator should be - ve but not both.

So if we multiply the numerator and denominator we should get a - ve number.

=> (x-3)(x+5)(x-7)|x-4|(x+6)<0

As we know that |x-4|is always a positive quantity we can say that the others’ product must be - ve.

So, x€{(-6,-5),(3,7)}……….(1)

And also for the given fraction to be =0, x=-5,3,7………(2)

Concluding the( 1) ,(2) we get the result to be that x€ (-6,-5]U[3,7].

Since x is not equal to 4,-6 (look on (0))

Therefore x € {(-6,-5]U[3,7]}-{4} or

x € {(-6,-5]U[3,4)U(4,7]}

(Sorry for the sign € (euro) it means ‘belongs to’)