Answer
graph of given equation $x + y = 1$ is a straight line as following-
Work Step by Step
Given equation-
$x + y = 1$
To sketch graph of this equation, first we will find three points on it as following-
Substituting $x = -2$ in given equation-
$-2 + y = 1$
OR $ y = 1+2 = 3$
Hence a point $P (-2, 3)$ lies on the line.
Now
Substituting $x = 0$ in given equation-
$0 + y = 1$
OR $ y = 1$
Hence another point $Q (0, 1)$ also lies on the line.
Now
Substituting $x = 1$ in given equation-
$1 + y = 1$
OR $ y = 1 - 1 = 0$
Hence another point $R (1, 0)$ also lies on the line.
Now we will mark the points $P, Q $ and $R$ on the graph paper and join these points to get the graph of given equation $x + y = 1$