Answer:
y = -1/2x +2
Step-by-step explanation:
The linear and quadratic function rules we usually study in algebra come in several forms.
For linear function rules (equations of a line), there are more than half a dozen different forms, each with its own use. A few that often come in handy are the 2-point form, the slope-intercept form, the point-slope form, and the intercept form. Here, the 2-point form can be useful, since you have several points on the line to choose from.
The 2-point form of the equation of a line is ...
y = (y2 -y1)/(x2 -x1)·(x -x1) + y1
point (x1, y1) and point (x2, y2) can be any pair of the given points, in any order. Let's use the first two for points 1 and 2.
y = (0 -1)/(4 -2)·(x -2) +1
y = -1/2(x -2) +1 . . . . . . . . this is a suitable function rule. In this simplified form, it is in point-slope form, where -1/2 is the slope and (2, 1) is the point.
If you want to simplify this a bit, you can put it into slope-intercept form by eliminating the parentheses and combining the constant terms:
y = -1/2x +2
(0.5 x 1.2)) x 2 = 0.6