1) line passing through (1, 7) and (3, 3)
2) line parallel to y= 5x-5
1) The line passing through (1, 7) and (3, 3) would have a slope, m, of
. . .m = [7 - 3] / [1 - 3]
. . .m = 4 / [-2]
. . .m = -2
The line passing through (1, 7) and (3, 3) would be y = -2x + b. To find a specific y-intercept, pick one of the given points and plug it in. Suppose you take the second point. Then, for x = 3 and y = 3, you get:
. . .y = -2x + b
. . .3 = -2[3] + b
. . .3 = -6 + b
. . .9 = b
. . .y = -2x + 9
And this last equation is your answer.
2) Any line parallel to y = 5x - 5 would have the same slope, m, of 5. The general equation would be y = 5x + b. This might be the expected answer. But any value for "b", other than the one they already used, would probably be acceptable, being one of the infinitely-many parallel lines possible.
Arthur
