
William W. answered 10/27/21
Math and science made easy - learn from a retired engineer
There are several different "generic" equations that denote a line. The most famous seems to be the slope-intercept form which is y = mx + b. Although you can use this form to solve the problem by inserting the slope 9/4 as "m" and then putting in the point (4, 1) as an ("x", "y") and then solving for "b", an easier way is to use the point-slope form of a line.
Point-Slope form: y - y1 = m(x - x1). You know "m" (which is 9/4) and you know (x1, y1) which is (4, 1) so plug those in to get:
y - y1 = m(x - x1)
y - 1 = 9/4(x - 4)
This is the answer although you can manipulate it a bit to make it look slightly different:
y - 1 = 9/4(x - 4)
y - 1 = 9/4x - 9
y = 9/4x - 8