Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
Given
x + y = 3 ( subtract x from both sides )
y = - x + 3 ← in slope- intercept form
with slope m = - 1
Given a line with slope m then the slope of a line perpendicular to it is
m_{perpendicular}m
perpendicular
= - \frac{1}{m}
m
1
= - \frac{1}{-1}
−1
1
= 1
