Number of real solutions of `sqrt(2x-4)-sqrt(x+5)=1` is
(a) 0 (b) 1 (c) 2 (d) infinite
A
`0`
B
`1`
C
`2`
D
infinite
Text Solution
Verified by Experts
The correct Answer is:
B
`(b)` We have `sqrt(2x-4)=1+sqrt(x+5)` Squaring `2x-4=1+(x+5)+2sqrt(x+5)` `implies x-10=2sqrt(x+5)` `implies x^(2)+100-20x=4x+20` `impliesx^(2)-24x+80=0` `impliesx=4,20` Putting `x=4`, we get `sqrt(4)-sqrt(9)=1`, which is not possible Putting `x=20`, we get `sqrt(36)-sqrt(25)=1` Hence, `x=20` is the only solution.