3(3x+1)=13-6x
1) Remove parenthesis by multiplying monomial times binomial.
2) Get all the terms containing a variable on the same side of the equation by adding and/or subtracting the same terms containing a variable to/from both sides of the equation.
3) Combine like terms.
4) Get all the terms not containing a variable on the same side of the equation by adding and/or subtracting the same terms not containing a variable to/from both sides of the equation.
5) Combine like terms.
6) Divide both sides of the equation by the coefficient of the term containing a variable.
7) Reduce fraction to lowest terms.
8) Check your answer by substituting the obtained value of x into the original equation and performing the arithmetic. If the resulting statement tells the truth, you have found the correct solution. If not, start over.
Next time, when you ask a question, please show us your work so far.