9the equation of a line in ' slope- intercept form ' is
y = mx + c ( m is the slope and c the y-intercept )
y = 3x + 1 is in this form
with slope = 3 and y-intercept = 1
the graph crosses the y- axis at ( 0, 1 )
from this point moving 3 units vertically up and 1 unit horizontally right gives the point (1, 4 ) . Repeating this gives the point (2, 7 )
Plot the points (0, 1 ), (1, 4 ) and (2, 7 )
Draw a straight line through them for graph of y = 3x + 1
