The X which is the first number in each () in called the input
There is only one input for every number
Meaning all the first numbers mystery br DIFFERENT
Hey there mate!
Please check the attached answer of picture for explanation.

Answer:
BD
AC
SN (might not be one)
AB
Step-by-step explanation:
Answer:
the diagonal of TV equal to 20
3r+1w=5
5r+1w=80
System of equations :)