Question

Irect Variation

liya Valerio is taking this assessment.
Iultiple Choice
1. Suppose y varies directly with x, and y = 14 when x = -4. What is the value of y when x = -6? (1 point)
0-21

Answer 1

For this case we have to by definition, if "y" varies directly with "x" then it is true that:

`y = kx`

Where:

k: Is the constant of proportionality

We find the constant "k" according to the given data:

`14 = k (-4)\\k = - \frac {14} {4} = -\frac {7} {2}`

Thus, the constant of proportionality is
`- \frac {7} {2}.`

Now, we find the value of "y" when
`x = -6:`

`y = - \frac {7} {2} (- 6)\\y = \frac {42} {2}\\y = 21`

Thus, when
`x = -6`, the value of y is 21.

ANswer:

`y = 21`