Question

Suppose y varies directly with x. Write an equation relating x and y.

y = −30 when x = 6
a.
y = −5x
c.
y = −36x
b.
y = 5x
d.
y = 36x

Answer 1

9514 1404 393

Answer:

a. y = -5x

Explanation:

The different signs of x and y tell you the constant of proportionality will be negative (eliminating choices b and d).

A quick trial of the given values shows that choice c is incorrect, and that choice a is correct.