Answer:
The constant of variation is k = -2 ⇒ (B)
Step-by-step explanation:
The equation of the direct variation is y = k x, where
- k is the constant of variation
- The constant of variation k =

The given table has 4 points (-1, 2), (0, 0), (2, -4), (5, -10)
We can use one of the points <em>[except point (0, 0)]</em> to find the value of k
∵ (-1, 2) is a given point
∴ x = -1 and y = 2
∵ k = 
→ Substitute the values of x and y in the relation above
∴ k = 
∴ k = -2
The constant of variation is k = -2
3(12)/10(12) + 7(10)/12(10) = 36/120 + 70/120
==> 18/60 + 35/60 = 53/60
To find the superficial area of a prism you have to do base perimeter * height
So find the perimeter of the right triangle: 9+8+5 = 22 yd
Then find the superficial area 22*12 = 264 yd^2