Question

Solve the system:
c+12d=-66
-4c+3d=-42

Answer 1

Answer: c=6, d=-6

Explanation:

c+12d=-66

-4c+3d=-42

(-4c+3d=-42)*4

-16c+12d=-168 ==> subtract this

c+12d=-66 ==> by this

-17c=-168-(-66) ==> subtract the top two equations

-17c=-168+66

-17c=-102

c=6

c+12d=-66

6+12d=-66

12d=-72

d=-6