Determine the equation of a line, in slope-intercept form, that passes through the points (9, -2) and (12, 0).

As x increases from 9 to 12 (a change of 3), y increases from -2 to 0 (a change of 2).  Thus, the slope of this line is 2/3.

Subbing this info and the coordinates of one of the points into y = mx + b, we get:

-2 = (2/3)(9) + b.  Solving for b:  b = -2 -18/3 = -8.  Then the equation of this line is:

y = (2/3)x - 8.

Check by subst.:  Does (12,0) satisfy this equation?  0 = (2/3)(12) - 8?  Yes.

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.