Answer: y=x
Step-by-step explanation:
[tex]x-y=7\\x-y+y=7+y\\x=7+y\\x-7=7+y-7\\x-7=y[/tex]
The line that parallel to the line x-y=7 is:
[tex]y=x+b[/tex]
The line that passes through the point P(-1,-1), hence:
[tex]-1=-1+b\\-1+1=-1+b+1\\0=b\\Thus,\\y=x+0\\y=x[/tex]
