WAEC - Further Mathematics (2024 - No. 3)
\(\sqrt{x}\) - \(\frac{6}{\sqrt{x}}\) = 1, find the value of x
36
16
9
25
Giải thích
\(\sqrt{x}\) - \(\frac{6}{\sqrt{x}}\) = 1
Multiply through by \(\sqrt{x}\)
x - 6 = \(\sqrt{x}\)
x - \(\sqrt{x}\) = 6
let \(\sqrt{x}\) = q, then x = q\(^2\)
q\(^2\) - q - 6 = 0
q\(^2\) - 3q + 2q - 6 = 0
q(q - 3) + 2(q - 3) = 0
(q - 3)(q + 2) = 0
q = 3 or -2
but x = q\(^2\), meaning, x = 9 or 4.