WAEC - Further Mathematics (2010 - No. 15)
If \(\begin{vmatrix} 3 & x \\ 2 & x - 2 \end{vmatrix} = -2\), find the value of x.
-8
4
-4
8
Spiegazione
\(\begin{vmatrix} 3 & x \\ 2 & x - 2 \end{vmatrix} = 3(x - 2) - 2x = -2\)
\(3x - 6 - 2x = -2 \implies x - 6 = -2\)
\(x = -2 + 6 = 4\)