Find the solution of the equation x - 8\(\sqrt{x}\) + 15 = 0
A
3, 5
B
-3, -5
C
9, 25
D
-9, 25
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
x - 8\(\sqrt{x}\) + 15 = 0
x + 15 = 8\(\sqrt{x}\)
square both sides = (x + 15)2 = (8 \(\sqrt{x}\)2
x2 + 225 + 30x = 64x
x2 + 225 + 30x - 64x = 0
x2 - 34x + 225 = 0
(x - 9)(x - 25) = 0
x = 9 or 25
Source: Myschool Past Questions Archive (Record #31460)