we have the system
7x-9y=13
-4x+5y=-8
in matrix notation
7 -9 x 13
=
-4 5 y -8
AX=B
where
A= 7 -9
-4 5
Find A^-1
Det A=(35-(36))
Det A=-1
the inverse matrix is equal to
-1 5 9 13 ------- > (5)(13)+(9)(-8) ------> -7
4 7 -8 (4)(13)+(7)(-8) -4
multiply by -1
-7*-1=7
-4*-1=4
therefore
the solution is (7,4)
option B