Answer
The x-intercept is (7,0), and the y-intercept is (0,3).
Work Step by Step
To find the x and y intercepts, we plug in 0 for y and x, respectively:
$ 3x +7(0) = 21 \\ x =7$
$3(0) + 7y = 21 \\ y =3 $
The x-intercept is (7,0) and the y-intercept is (0,3).
To draw the graph, plot each of these points, and then draw a lie that goes through both.