If y varies directly as x and y = 24 when x = -3, find the constant of variation k and then determine y when x = 12.

I. k = -8

II. y = -96

Step-by-step explanation:

Given the mathematical expression and data;

y = 24

x = -3

y = kx (y varies directly as x).

To find the constant of proportionality k;

y = kx

Substituting the values into the expression, we have;

24 = k(-3)

24 = -3k

k = -24/3

k = -8

Next, to find the value of y when x = 12

y = kx

Substituting the values, we have;

y = -8 * 12

y = -96

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.