Answer:
$57.5 is the total cost to build the pen.
Step-by-step explanation:
We are given the following in the question:
A livestock pen is built in the shape of a rectangle.
The length of rectangle is two times the width.
Let l be the length of rectangle and w be the width of rectangle. Thus, we can write

Perimeter = 30 feet

Putting values,

The length of rectangle is 10 feet and width of rectangle is 5 feet.
If the material used to build the pen is $ 1.75 per foot for the longer sides and $ 2.25 per foot for the shorter sides
Cost of building =

Thus, $57.5 is the total cost to build the pen.
4 to 7
or
4+7= 12
4x+7x=33
x=3
so,
(4×3)+(7×3)=33
12+21=33
or
12 and 21.
hope it helped
69,420,911,80085 and that’s all