7) In the barn there are 17 animals. Some are cows and some are ducks. There are 54 legs in all. Which system of equations below could be used to find how many cows and how may ducks are in the barn?

A) c+d=17
4c+2d=54

B) c+d=17
4c+2d=54

C) c+d=17
4c+2d=17

D) c+d=17
4c+2d=6cd

Either A or B

Step-by-step explanation:

Both A and B are the same answers, but the main answer should be

c+d=17, 4c+2d =54

C represents the number of cows and D represents the number ducks. The two and fours in front of the variables represents the number of legs the repesctive animal has.

c+d would mean how many animals are in the barn. Feel free to clarify the two same answers

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.