The perimeter of the figure shown is 35 centimeters.

a. Write an equation that you can use to find x.

b. Solve your equation. What is the value of x?

An equation is a mathematical statement that two expressions are equal. The solution of an equation is the value that when substituted for the variable makes the equation a true statement.

Example: 3x + 5 = 14 is an equation, in which 3x+5 and 14 are two expressions separated by an ‘’equal’’ sign.

Step 1: Simplify each side of the equation by removing parenthesis and combining the like terms.

Step 2: Use addition or subtraction to isolate the variable term on one side (preferably in the left side).

Step 3: Use Multiplication or Division to solve for the variable.

The perimeter of the figure is 35 cm and the perimeter is the sum of all sides.

Perimeter = sum of all sides

An equation is a mathematical statement that two expressions are equal. The solution of an equation is the value that when substituted for the variable makes the equation a true statement.

Example: 3x + 5 = 14 is an equation, in which 3x+5 and 14 are two expressions separated by an ‘’equal’’ sign.

Step 1: Simplify each side of the equation by removing parenthesis and combining the like terms.

Step 2: Use addition or subtraction to isolate the variable term on one side (preferably in the left side).

Step 3: Use Multiplication or Division to solve for the variable.

The equation x + 31 cm $=35$cm

Solve the equation step by step

$\begin{array}{l}x+31\text{\hspace{0.17em}\hspace{0.17em}cm\hspace{0.17em}\hspace{0.17em}}=35\text{\hspace{0.17em}\hspace{0.17em}cm}\\ \Rightarrow \text{\hspace{0.17em}\hspace{0.17em}x+31\hspace{0.17em}\hspace{0.17em}cm\hspace{0.17em}\hspace{0.17em}-\hspace{0.17em}\hspace{0.17em}31\hspace{0.17em}\hspace{0.17em}cm\hspace{0.17em}\hspace{0.17em}=\hspace{0.17em}\hspace{0.17em}35cm\hspace{0.17em}\hspace{0.17em}-\hspace{0.17em}\hspace{0.17em}31\hspace{0.17em}\hspace{0.17em}cmSubtract31cmfrombothsides}\\ \Rightarrow x=4\text{\hspace{0.17em}\hspace{0.17em}cm}\end{array}$