Question 203846
Find the numbers C and D such that (-4,-7) is a solution of the following system:

-4x + Cy =-3
Dx - 2y = 24
:
Substitute -4 for x and -7 for y
-4(-4) + C(-7) = -3
D(-4) - 2(-7)  = 24
:
+16 - 7C = -3
-4D + 14 = 24
:
-7C = -3 - 16
7C = 3 + 16
C = {{{19/7}}}
and
-4D = 24 - 14
-4D = 10
D = {{{10/(-4)}}}
D = {{{-5/2}}}