91Ó°ÊÓ

In an algebraic expression, terms are separated by plus or minus signs.

The term coefficient refers to the number in front of the variable in any term of the expression.

A constantterm is the number which have no variable associated with it.

Like terms are the terms which have identical variable parts with same exponent on it. Constants are considered to be like terms as well.

The perimeter of a closed figure, formed by some line segments (sides) connected at most one point (vertex), is the sum of all the sides of the figure.

The perimeter of the triangle is given by the sum of all three sides of the triangle.

To find the expression for the perimeter of the given triangle, add all three side lengths as shown below

$\text{Perimeteroftriangle}=a+2a+(10−3a)$

To simplify above expression, remove the parenthesis then group the like terms and combine the like terms as shown below

$\begin{array}{c}\text{Perimeteroftriangle}=a+2a+(10−3a)\\ =a+2a+10−3a\\ =a+2a−3a+10\\ =(1+2−3)a+10\\ =(3−3)a+10\\ =\left(0\right)a+10\\ =10\end{array}$

Thus, the perimeter of the triangle is 10.