Given:
A straight-line graph has gradient 4 and crosses the y axis at (0, −3).
To find:
The equation of the given graph.
Solution:
The slope intercept form of a line is:
[tex]y=mx+b[/tex] ...(i)
Where, m is the slope of the line and b is the y-intercept.
A straight-line graph has gradient 4. It means the slope of the line is 4.
[tex]m=4[/tex]
Line crosses the y axis at (0, −3). So, y-intercept is -3.
[tex]b=-3[/tex]
Putting m=4 and b=-3 in (i), we get
[tex]y=(4)x+(-3)[/tex]
[tex]y=4x-3[/tex]
Therefore, the equation of the given line graph is [tex]y=4x-3[/tex].
