If [2x 4][ x −8 ] = 0, find the positive value of x.

Question

If [2x 4]\(\begin{bmatrix} x \\-8 \end{bmatrix}\) = 0, find the positive value of x.

Answer 1

We have [2x 4] \(\begin{bmatrix} x \\-8 \end{bmatrix}\) = 0

⇒ 2x × x − 4 × −8 = 0 

⇒ 2x² − 32 = 0 

⇒ x² = 16 

⇒ x = ±4.

Hence, if [2x 4] \(\begin{bmatrix} x \\8 \end{bmatrix}\)= 0 then positive value of is = 4.