The perimeter of a triangle is the sum of all side lengths of the triangle. The numerical expression for the perimeter of Stephanie's triangle is: 
Let the sides of Juan's triangle be x, y and z. So:

The perimeter (J) of Juan's triangle is calculated by adding all sides.
So:

This gives:


From the question, we understand that:
The perimeter (S) of Stephanie's triangle is half that of Juan.
This means that:

Substitute 25 for J

Hence, the numerical expression for the perimeter of Stephanie's triangle is: 
Read more about perimeters at:
brainly.com/question/11957651
Answer:
Step-by-step explanation:
12,800 written as 1.28 x 104 in scientific notation
<span>What percent of 40 is 25?
Let x = what percent
of = multiplication
is means =
We now write it in math terms:
x times 40 = 25
40x = 25
Divide both sides by 40 to find x.
x = 25/40
x = 0.625
Change the decimal number 0.625 to a percent.
x = 62.5%
</span>
Answer:
19x - 5y - 6
Hope this helped
Step-by-step explanation:
You start by simplifying each expression, you will be distributing the number outside the parentheses on each number inside the parentheses
1/2(30x+4y-14)
1/4(16x -28 +4)
leaving you with
15x + 2y - 7 + 4x - 7y + 1
combine the x's y's and the singular numbers
19x - 5y - 6
Brainliest?