The answer depends on how advanced your methods are. In general, the methods are the same except that if you have repeating decimals, they may cause rounding errors.
Yes
By eliminating the fractions
yes, but not recommended
The answer will depend on the form of the equation. Whether it is an equation in one or more variables, whether it is linear or polynomial, there are different standard forms for exponential equations.
You cannot solve fractions. There may be sums or products containing fractions or equations that can be solved. But fractions themselves cannot.
6.6/0.2
Assuming you want to get rid of the fractions, you can multiply both sides of the equations by the greatest common factor of the fractions. Then you can solve the equation normally.
Equations can be tricky, and solving two step equations is an important step beyond solving equations in one step. Solving two-step equations will help introduce students to solving equations in multiple steps, a skill necessary in Algebra I and II. To solve these types of equations, we use additive and multiplicative inverses to isolate and solve for the variable. Solving Two Step Equations Involving Fractions This video explains how to solve two step equations involving fractions.
To eradicate the denominators.
The Subscripts in a Chemical formula explain how the atoms in that compound are chemically bonded. As a fraction of an atom cannot bond, the subscripts cannot be fractions. Coefficients, however which go before a chemical formula in chemical equations may be fractions. This is because they explain the ratio of the number of moles of each species required for the reaction and it is possible to have a fraction of a mole of something. The Subscripts in a Chemical formula explain how the atoms in that compound are chemically bonded. As a fraction of an atom cannot bond, the subscripts cannot be fractions. Coefficients, however which go before a chemical formula in chemical equations may be fractions. This is because they explain the ratio of the number of moles of each species required for the reaction and it is possible to have a fraction of a mole of something.
Not necessarily, but often it is simpler to convert fractions into decimals to solve the equation.