Choose the graph that best represents the solution to the system of equations.
y=-x
y=x-1

Given system of equations,

y = - x   ------(1)

y = x - 1 ------(2),

From equation (1) and (2),

-x = x - 1

-x - x = -1

-2x = -1

Again from equation (1),

Thus, the intersection point of the lines (1) and (2), is

Hence, the below graph represents the solution to the system of equations.

the answer to your question is b.