Answer:
When (-1,-4) is substituted into the first equation, the equation is true.
When (-1,-4) is substituted into the second equation, the equation is true.
Step-by-step explanation:
The given system is
x-y=3
7x-y=-3
Make x the subject in the top equation to get:
x=y+3
Put x=y+3 in the bottom equation to get:
7(y+3)-y=-3
Expand
7y+21-y=-3
7y-y=-3-21
6y=-24
y=-4
Put y=-4 into x=y+3 to get
x=-4+3=-1
Hence the point (-1,-4) is a solution to both equation
