Question
Mathematics Question on complex numbers
The number of positive integral solutions of (x−5)5(2x−7)6x2(3x−4)3(x−2)4≤0 is .
A
4
B
3
C
2
D
1
Answer
3
Explanation
Solution
(x−5)5(2x−7)6x2(3x−4)3(x−2)4≤0 ⇒x=0,34,2,3x−4<0,x−5>0 or 3x−4>0,x−5>0 [∵x2,(x−2)4,(2x−7)6>0] ⇒x=0,34,2,x<34,x>5 or x>34,x<5 ⇒x=0,2 and integral value between 34<x<5 i.e., x=2,3,4. Hence positive integral solutions are 2, 3, 4.