Final answer:
To find the equation of the variation function, use the formula y = mx + b. Find the slope using the formula m = (y2 - y1) / (x2 - x1). Plug in the slope and one of the points into the equation and solve for b.
"The correct option is approximately option A"
Step-by-step explanation:
To find the equation of the variation function, we can use the formula y = mx + b, where m is the slope and b is the y-intercept.
Given that the function contains the points (-9, -3) and (-12, -4), we can find the slope using the formula m = (y2 - y1) / (x2 - x1). Plugging in the values, we get m = (-4 - (-3)) / (-12 - (-9)) = -1/3. Now we can plug in the slope and one of the points into the equation and solve for b. Let's use the point (-9, -3). So, -3 = (-1/3)(-9) + b.
Simplifying, we have -3 = 3 + b. Subtracting 3 from both sides, we get b = -6. Therefore, the equation of the variation function is y = (-1/3)x - 6. Therefore, the correct answer is a. y - 1 = 6x.