math
posted by ashton .
If the line passing through the points (a, 1) and (5, 7) is parallel to the line passing through the points (8, 8) and (a + 2, 1), what is the value of a?
a =?

since the slopes are the same,
6/(5a) = 7/(a+28)
6(a6) = 7(a5)
6a36 = 7a35
a = 1