algebra
posted by samuel on .
Determine whether or not the relation is a function. (3,6), (2,7, (1,8), (0,9)

sketch a graph.
one value of y for every value of x
certainly a function
In fact a straight line of form y = mx+b
slope = 1 goes through those points
y = x + b
9 = 0 + b
b = 9
so a function that easily fits those points is
y = x + 9