Question

What is the equation of the line that passes through the points (-2, 3) and (2, 7)?

x - y = -1

x - y = -2

x - y = - 5

x - y = - 6

Answer 1

@thomaster

Answer 2

plug both points into the equation and see for which the left hand side equals the right hand side. If they're both true, the equation is correct.

Answer 3

Example:
(-2, 3), (2, 7)
-2 - 3 = -5 != -1, so you know that the first one is incorrect.

Answer 4

Of course, you can always find the slope, and then the equation of the line via m = (y2-y1)/(x2-x1), but I find this way to be easier.

Answer 5

so it would be c??

Answer 6

You are correct :)

Answer 7

Thanks

Answer 8

One very important point here is that you must check BOTH of the points! The equation is correct only if both of the points work. A savvy test-writer would put in an equation or two that matches only one of the points...