Question

If y varies directly with x, and y =24 when x=-15. What is x when y=15.

Answer 1

y = (75/8) or 15.6 when y = 15

Step-by-step explanation:

" y varies directly with x" may be written as y = Kx, where K is the constant of proportionality (or slope).

We can calculate K with the one given solution (15,24):

y = Kx

24 = K*15 for (15,24)

K = (24/15) or (8/5)

y = (8/5)x

For y = 15:

y = (8/5)x

15 = (8/5)x

x = 15*(5/8)

x = (75/8) or 15.6

Answer 2

The value of x, when y=15 is -9.375, given that y, varies directly with x and y=24 when x=-15.

Step-by-step explanation:

The question asks us to determine the value of x when y=15, given that y varies directly with x and that y=24 when x=-15. To solve this, we first find the constant of variation by dividing y by x for the values given: k = 24 / (-15). Using this constant, we can then set up an equation for y in terms of x expressed as y = k x. From that, we can substitute y=15 and solve for x.

Step 1: Determine the constant of variation (k)
k = y / x = 24 / (-15) = -1.6

Step 2: Set up the equation with the constant
y = kx

Step 3: Plug in y=15 and solve for x
15 = (-1.6)x
x = 15 / (-1.6)
x = -9.375

The value of x when y=15 is -9.375.