Find the value of x2 + 17 if
\(\sqrt {4x - 9}\) + \(\sqrt {4x + 9}\) = \(\sqrt {25}\) + \(\sqrt {7}\)
Answer & explanation
Correct answer: option 3
We can easily see that x = 4 will satisfy the expression:
⇒ \(\sqrt {4x - 9}\) + \(\sqrt {4x + 9}\) = \(\sqrt {25}\) + \(\sqrt {7}\)
⇒ \(\sqrt {16 - 9}\) + \(\sqrt {16 + 9}\) = \(\sqrt {25}\) + \(\sqrt {7}\)
⇒ \(\sqrt {7}\) + \(\sqrt {25}\) = \(\sqrt {25}\) + \(\sqrt {7}\)
Hence,
x2 + 17 = 42 + 17 = 16 + 17 = 33