Question

if (-2 1 x+2 )
(3 x-4 5 ) =25
(0 1 3 )

p/s : all the value above in one bracket ( )


a) find the value of x

b) hence ,find (-2 1 x+2 )^-1
( 3 x-4 5 )
(o 1 3 )

p/s : all the value above in one bracket ( )

Answer 1

assuming you mean a determinant, and calling your matrix M, I get

|M| = 31-3x

So, if 31-3x = 25, x=2

The inverse can be seen at

http://www.wolframalpha.com/input/?i=inverse+{{-2%2C+1%2C+x%2B2}%2C{3%2C+x-4%2C+5}%2C{0%2C+1%2C+3}}+

substitute in x=2 if you just want the numbers.