WAEC - Mathematics (2023 - No. 10)
For what value of x is \(\frac{ x^2 + 2 }{ 10x^2 - 13x - 3}\) is undefined?.
\(\frac{1}{5}, \frac{3}{2}\)
\(\frac{-1}{5}, \frac{3}{2}\)
\(\frac{1}{5}, \frac{-3}{2}\)
\(\frac{-1}{5}, \frac{-3}{2}\)
설명
The fraction \(\frac{ x^2 + 2 }{ 10x^2 - 13x - 3}\) is undefined when the denominator is equal to zero
\(then 10x^2 - 13x - 3 = 0\)
by factorisation, \(10x^2 - 13x - 3\) = 0 becomes \( 10x^2 - 15x +2x -3\) = 0
\(5x(2x - 3) + 1(2x - 3) = 0\)
\((5x + 1)(2x - 3) = 0\)
\(then, x = \frac{-1}{5}\) or \(\frac{3}{2}\)