SYSTEM A: which of the following shows the equation that creates a true equivelent system

-x+y=1
x+y=11
SYSTEM B:
x+y= 11
?
A: 2x+2y=12
B: -2x - 2y = -22
C: -x - y = -1
D:2y=12

The correct answer is C: -x - y = -1.

To create a true equivalent system, you would simply multiply the first equation in System A by -1 to get: x - y = -1. This equation is equivalent to -x - y = -1.