Question

Use the table to write the rule (equation) for the relationship between x and y. Y 1 3 5 1 8

Answer 1

X Y

1 1

3 -5

4 -8

line equation: y = mx + b

slope = m = (y2 - y1)/(x2 -x1) = (-8 + 5)/(4 - 3) = -3/1 = -3

y = mx + b, using last point and m = -3, we can write:

-8 = -3(4) + b = -12 + b

b = -8 + 12 = 4

b = 4

Line equation: y = -3x + 4

Answer:

y = -3x + 4