Michael breeds chickens and ducks. Last month, he sold 50 chickens and 30 ducks for $550. This month, he sold 44 chickens and 36 ducks for
$532.
How much does a chicken cost, and how much does a duck cost?
A chicken costs S
a and a duck costs

50C + 30D = 550 (1)

44C + 36D = 532 (2)

(2) - (1)

6C - 6D = 18

Divide both Sides by 6

C - D = 3

C = (3 +D) (3)

Substitute 3 in 1

50(3 +D) + 30D = 550

150 + 50D + 30D = 550

80D = 550 -150

80D = 400

D = 400÷80

D = 5

C = (3+ D) (3)

C = 3+5

C = 8

Chicken costs $8.

Duck costs $5.

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.