Question

Given the following set of ordered pairs, determine if it is direct or inverse variation and find the value of k. (2, -10) (4, -20) (7, -35) (8, -40)

Answer 1

Answer:

direct variation

Step-by-step explanation:

The constant of variation k for direct variation is

k = $\frac{y}{x}$

Calculate this ratio for each set of points

$\frac{-10}{2}$ = $\frac{-20}{4}$ = $\frac{-35}{7}$ = $\frac{-40}{8}$ = - 5

Then ordered pairs are in direct variation with k = - 5

The constant of variation for inverse variation is

k = xy

2 × - 10 = - 20

4 × - 20 = - 80

7 × - 35 = - 245

8 × - 40 = - 320

There is no constant thus not inverse variation