Paper 4: Fundamentals of Business Mathematics & Statistic

FUNDAMENTALS OF BUSINESS MATHEMATICS AND STATISTICS I 2.55

or, (u + 6) (u – 4) = 0 or, u = – 6, u = 4
For u = – 6, x^2 + 3x = – 6 or, x^2 + 3x + 6 = 0

x 3 9 24 3 15,

2 2

=− ± − =− ± − rejected as values are not real

For u = 4, x^2 + 3x = 4 or, x^2 + 3x – 4 = 0
or (x + 4) (x – 1) = 0 or, x = – 4, 1.

SELF EXAMINATION QUESTIONS

1. 6x^2 –11x – 10 = 0. [Ans. 2 35 2,− ]


2. (2x – 1)1/3 = (6x – 5)1/3 [Ans. 1]


3. x+x 31 10=. [Ans. 3, 31 ]


4. 4x+x^4 =^17 [Ans. 4, 41 ]


5. x a b x a b+^1 + =1 1 1+ + [Ans. – a, – b]


6. x 3 13 x 4+ =4. [Ans. 12,^34 ]


7. 7x 30 x6 x 3− =. [Ans. ± 6]


8. 3 + = .x 3x 31 10 [Ans. ± 1]


9. 2x–1 + x–1/2 = 6. [Ans. 4 91 4, ]


10. −− x32x =+ .322 [Ans. 2, 3]


11. 1 x−x + 1 x 13−x 6= [Ans. 13 139 4, ]