Portia drew a line on the coordinate plane that passed through the points (-3,19) and (2,9). which equation represents the line that portia drew?

To make an equation we need to put into a slope intercept form. 
The formula is Rise/run or y-y/x-x
so it is -3 - 2/19-9 which is -5/10
so the slope is -1/2
so the equation right now is y=-1/2x+b
then we need to find the y intercept which we can use a graphing website to find the y-intercept which is on the y-axis and it is about 10 so the equation is
y=-1/2x+10.
The equation and answer is y=-1/2x+10
Hope this helps!