Answer:
14a. x=3, y=-1
14b. 12
14c. 40
Explanation:
Opposite sides have to be equal, so you can write the following equations:
4 x + 2 y = x - 3 y + 4
2 x + 2 y = x - y
Simplify both:
3x + 5y = 4
x = - 3y
Plug the second into the first:
-9y + 5y = 4
-4y = 4
y = -1
so
x = -3*-1 = 3
The perimeter is a matter of filling in x and y in the formulas:
10 + 4 + 10 + 4 = 32
Now that we know the side lengths 4 and 10, the area is their multiplication
4*10 = 40