## Combined Operations theory

# Combined Operations

We call **Combined Operations** to those in which several arithmetic operations appear to be solved. To get the right result you need to follow some rules and take into account the priority between different operations.

There are several types of combined operations:

First we must solve the powers, then products and quotients and finally addition and subtraction.__Without plain brackets:__

First we perform the operations contained in plain brackets in the order of priority. Next, we remove parentheses solving the operations.__With plain brackets:__

First we operate with the powers, products and quotients which are in plain brackets, we solve all the additions and subtractions of the plain brackets and instead of square brackets, we write parentheses directly. After this we multiply and finally we solve additions and subtractions.__With square brackets:__

In the case of **operating with fractions**, first we must solve products and mixed numbers that are in different brackets. After this, a simplification is made by replacing the square brackets by plain ones and solving the operations that there are within them. Finally, the numerator operations will be done, next we do the division and finally, we simplify the result:

__With curly brackets__Firstly we operate with the powers, products and quotients which are in plain brackets, next we do additions and subtractions of plain brackets. Then we write square brackets instead of plain brackets directly and where we had curly brackets we write square ones, we operate inside the plain brackets, we put parentheses and finally we do additions and subtractions.__:__

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You can download the App **BioProfe READER** to practice this theory with **self-corrected exercises**.