A=([-2,-3,4],[3,4,-5],[3,5,-6]),B=([2,x,y],[9,2,-4],[8,3,-2]),(x,yinR)
Find
x
and
y
such that
AB
is a triangular matrix. Write down this triangular matrix and give its determinant. Without any additional calwlations, deduce that
A
is invertibte.