Answer:
Option 1st is correct

Step-by-step explanation:
Area of the triangle is given by:

where,
A is the area of the triangle
b is the base and
h is the height of the triangle.
As per the statement:
For a project, you need to make three triangles out of cardboard.
Each triangle has a height of 5 inches and a base of 10 inches
⇒b = 10 inches and h = 5 inches

Since, you need to make three triangles out of cardboard
⇒
Therefore, an equation can you use to solve for the total amount of cardboard you will need is,

We'll do the distribute property for both.
1/2x6x=3x
1/2x-10= -5
SO....
3x-5+ -4x +30
Which is
-x + 25 or 25-x.
Hope this helps!
5 16/25 is the greatest and -18/25 is the least if I'm correct