Answer:
1. Write the addition of "a", "b" and "c".
2. The equation is: 
Step-by-step explanation:
You know that <em>P</em> represents the perimeter of the triangle and <em>a, b </em>and <em>c </em>represent the sides of the triangle.
By definition, the sum is the result of an addition. Therefore, the statement "The perimeter <em>P</em> of a triangle is equal to the sum of the lengths of sides <em>a, b</em>, and <em>c</em>”, indicates that the perimeter is obtained by adding the lengths of the sides of the triangle.
Knowing this, you can write the following equation:

Answer:
9/16 into a decimal is 0.5625
A + s = 279
s = 2a
a + 2a = 279
3a = 279
a = 279/3
a = 93 <=== adult
s = 2a
s = 2(93)
s = 186 ....students
45
Find ten percent of 50 by moving the decimal point left once and subtract it from 50