Question

Suppose y varies directly with x and when y=10 when x=-3. What direct variation equation relates x and y? What is the value of y when x =-1?

Answer 1

Answer:

$y=\frac{10}{3}x$

y = -10/3

Step-by-step explanation:

We have been given that y varies directly with x. Thus, we have the equation

$y=kx$

when y=10 when x=-3

$10=k(3)$

Divide both sides by 3, we get

$k=\frac{10}{3}$

Thus, the equation which relates x and y is given by

$y=\frac{10}{3}x$

Now, we have to find the value of y when x = -1

$y=\frac{10}{3}(-1)\\\\y=-\frac{10}{3}$

Answer 2

Suppose y varies directly as x, and y=-65 when x=-26. Write a direct variation equation that relates x and y.
.
If "y varies directly as x" it is in the form of:
y = kx
where k is a constant
.
Using the values provided, you can find k.

y = kx
-65 = k(-26)
-65/(-26) = k
2.5 = k
.
So, our equation is:
y = 2.5x