How do u calculate the value of W ??

Question

How to find the w value in this matrix equation ??

 

w    -9

4  w-12

 

" Determinant is equal to 0 "

 

Answer 1

The determinant of the 2 by 2 matrix

 

     a     b     

                is ad - bc

     c      d

              

           w      -9

So, if                     = 0, then 

           4      w-12

 

      w² -12w + 36 = 0

 

      (w-6)² = 0     Therefore, w = 6

 

Answer 2

a matrix is an array of values.  your matrix is a 2 by 2 (square) matrix,

this is not an equation.

if you had a problem such as "the determinant of this matrix equals some particular number" then you would have a problem that could be solved.