I presume they are asking you to derive the equation of the line that has:

slope of 6 and a y intercept of -3

Method 1:

"Slope-intercept" of a line:

y = mx + b

where m is the slope and b is the y-intercept

plug in the given data and you're done:

y = 6x + (-3)

y = 6x - 3 (answer in "slope-intercept" form)

Method 2:

since the y-intercept is -3, it basically gives us one point (0, -3) on the line.

Plug the above point, and the slope into the "point-slope" form:

y - y1 = m(x - x1)

y - (-3) = 6(x - 0)

y + 3 = 6(x)

y = 6x -3 (this is what they're looking for in "slope-intercept" form)