JAMB - Mathematics (2010 - No. 9)
If \(\begin{vmatrix} x & 3 \\ 2 & 7 \end{vmatrix} = 15\), find the value of x
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Magyarázat
\(\begin{vmatrix} x & 3 \\ 2 & 7 \end{vmatrix} = 15\)
x x 7 - 2 x 3 = 15
7x - 6 = 15
7x = 15+6
7x = 21
x = 21/7
x = 3
x x 7 - 2 x 3 = 15
7x - 6 = 15
7x = 15+6
7x = 21
x = 21/7
x = 3