An equation in slope-intercept form that represents the relationship shown on the graph is y = 3/2(x) + 3.
In Mathematics and Geometry, the point-slope form of a straight line can be calculated by using the following mathematical equation (formula):

Where:
- x and y represent the data points.
- m represent the slope.
First of all, we would determine the slope for this table by using these points (2, 6) and (-2, 0);

Slope (m) = (0 - 6)/(-2 - 2)
Slope (m) = -6/-4
Slope (m) = 3/2
At data point (-2, 0) and a slope of 3/2, an equation for this line can be calculated by using the point-slope form as follows:

y - 0 = 3/2(x + 2)
y = 3/2(x) + 3