Ineed on numbers 13 and 17 ! show work for brainlest answer : ))

13.

17. Neither direct variation nor inverse variation.

Step-by-step explanation:

13. The diameter of gear (d) and the force (f) required to make it rotate at a constant rate are inversely proportional.

So, the product of the variables d and f is constant.  

Now, for d = 9 inches , f = 40 pounds and the product is 360

And for d = 12 inches , f = 30 pounds and the product is 360

Therefore, the relation between d and f is . (Answer)

17. y = -6x relation is neither direct variation nor inverse variation. (Answer)

351.23

step-by-step explanation:

the inequality is:

250c+180g≥950

step-by-step explanation:

let c denotes the number of days in a week   miyoko worked as a cryptographer.

and g denotes the number of days in a week she works as a geologist.

now we are given that she earns $250 for every day she works as a cryptographer,and earns $180 for every day she works as a geologist.

now miyoko's goal is to earn more than $950 this week.

hence, the inequality could be represented as:

250c+180g≥950