Answer:
Step-by-step explanation:
More than anything else, Algebra is a procedure. It has rules and axioms which when followed produce answers to problems -- problems that may not yield anything without Algebra.
These axioms and rules are familiar to anyone who has taken a course in advanced Mathematics. So each person who knows the procedure knows also how mathematics can work. It is a universal language spoken by those trained in what it offers to the education of both the "sender" and the "receiver."
we have

Step 
Move the constants to the right side

Step 
Factor 3 out of the variable terms

Step 
Add
to both sides of the equation


Step 
Write the polynomial as a binomial squared

therefore
the answer is
Factor 3 out of the variable terms.
R=17/3 alternative form would be r= 5 2/3, r=5.6 those would all be the answers depending on what form you need
<em>Hey </em><em>mate!</em><em>!</em>
<em>Answer:</em>
<em>n(</em><em>A)</em><em>=</em><em>1</em><em>2</em>
<em>Solution</em><em>,</em>
<em>A=</em><em>{</em><em>3</em><em>,</em><em>6</em><em>,</em><em>9</em><em>,</em><em>1</em><em>2</em><em>,</em><em>1</em><em>5</em><em>,</em><em>1</em><em>8</em><em>,</em><em>2</em><em>1</em><em>,</em><em>2</em><em>4</em><em>,</em><em>2</em><em>7</em><em>,</em><em>3</em><em>0</em><em>,</em><em>3</em><em>3</em><em>,</em><em>3</em><em>6</em><em>}</em>
<em>Just </em><em>count </em><em>the </em><em>elements</em><em>,</em>
<em>There </em><em>are </em><em>1</em><em>2</em><em> </em><em>elements </em><em>in </em><em>the </em><em>set.</em>
<em>So </em><em>the </em><em>cardinal </em><em>number </em><em>of </em><em>the </em><em>set </em><em>is </em><em>1</em><em>2</em><em>.</em>
<h2>
<em>Hope </em><em>it </em><em>helps.</em><em>.</em><em>.</em></h2>