This week’s topic is: Distance, Midpoint, and Slope.
Q: The slope of the line passing through (-1,-3) and (7,y) is -1/2. What is the value of y?
Algebraic solution by hand:
Use the slope formula:
Solution using my TI-84 Plus program DISTANCE:
Use your multiple choice answer choices. One of them is -7. (If you don’t have choices, draw a picture. Plot the point (-1,-3) and do a slope of -1/2 from there – down 1, right 2, down 1, right 2, … until you get to a point where x is 7. Read the y-value of that point – it will be -7 and check it using this program.)
Ignore the distance information – we don’t need it for this problem. Press ENTER for the midpoint information, which we don’t need either. Press ENTER once more to find that the slope is -1/2.