If the determinant of this matrix is -19, what is the value of a?

a.
3
b.
4
c.
5
d.
6

C)5

Step-by-step explanation:

For a 3x3 matrix

determinent is given by = = a(ei − fh) − b(di − fg) + c(dh − eg)

Given Matrix

determinent of matrix= -6((-3)(-3) − (4)(4)) − 7(a(-3) − (4)(-6)) + 1(a(4) − (-3)(-6))

-19= -6(9-16) - 7(-3a+24) +4a-18

125= 25a

125/25= 25a/25

a= 5 !

both equations and proportions are better.