#4 Help. ​

4)

Here's the equation we need :

r = ks / t

And when r = 2, s = 3

So .......  we need to find k

2  = k* 3 / 12        

2 = (1/4) k      multiply both sides by 4

8  = k

So

r  =  8 (5) / 4

r  =  40 / 4

r = 10

5)   Here's what we need

N =  k * A / P

The second sentence translates to :

1800  = k * 34000 / 25         multiply both sides by 25 / 34000

25 * 1800 / 34000  =  k  =  45/34

So we have

N  =  (45/34) * 42000 / 25     =    2224  dolls