A line through the points (2, -9) and (j, 17) is parallel to the line 2x + 3y = 21. What is the value of j?

Arrange line equation into form y = mx+b    m = slope        (parallel slope will be the same value)

2x+3y = 21

y = -2/3x +7       slope = -2/3

 

Now use your two points to calculate slope = - 2/3

(y1-y2) / (x1-x2) = slope = -2/3

(-9 - 17) / (2-j) = - 2/3          solve for 'j'