Answer:
y = x - 3
Explanation:
the equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
here m = 1 , then
y = x + c ← is the partial equation
to find c substitute (2, - 1 ) into the partial equation
- 1 = 2 + c ⇒ c = - 1 - 2 = - 3
y = x - 3 ← equation of line