Answer: The slope of the line that passes through (2, 12) and (4, 20) is 4.
The value of the y-intercept is 9.
Step-by-step explanation:
Slope of line passing through (a,b) and (c,d) = 
Then, the slope of the line that passes through (2, 12) and (4, 20) = 

So, the slope of the line that passes through (2, 12) and (4, 20) is 4.
To find the y-intercept of 3x + 2y = 18, first write in slope intercept form y=mx+c ( where c= y-intercept ).

By comparison, c= 9
Hence, the value of the y-intercept is 9.