Hello! This mainly depends on what equation you're solving buy follow PEDMAS (Parentheses,Exponents,Divison/Multiplication,and Addition/Subtraction.) This is your order of operations whether the equation has a variable or not. Here's an example:
2(60-45)7+6
Parentheses first so now you have 2(15)7+6. Multiply 2 times 15, you have (30)7+6. Add and multiply and your final result is 187. Remember that if there is no sign (like (30)7 it means multiplication)
Equations with variables are similar. Here's an example:
5+3n=17. Subtract 5 from both sides. Now you have 3n=12. You always do the opposite operation. Since three is being multiplyed by n, you divide on both sides. 12 divided by 3 equals 4. :D