The number of solutions of the equation ( 9x - 9 x + 2 ) ( 2x - 7 x + 3 ) = 0 is :
- 3
- 2
- 1
- 4
Answer
(4) 4
Solution
Let t = 1 x, t > 0 (x > 0 for the equation to be defined).
First factor: 9t2 - 9t + 2 = 0 (3t - 1)(3t - 2) = 0
t = 13, 23 x = 9, 94
Second factor: 2t2 - 7t + 3 = 0 (2t - 1)(t - 3) = 0
t = 12, 3 x = 4, 19
All four values are positive and distinct.
Number of solutions = 4
Answer: (4)