Sometimes when grouping symbols are use to enclose other grouping symbols, we use instead of parentheses or brackets, to make an expression easier to read.

Example: 2{(3 + 5)[2 −(4 + 5)] + 8

Sometimes when grouping symbols are use to enclose other grouping symbols, we use braces instead of parentheses or brackets, to make an expression easier to read.

Step-by-step explanation:

To group numbers or variables, brackets and braces are mostly used. Generally, they are used after parentheses. Parentheses are to be used first, then brackets, and then braces: {[( )]}.

However, instead of brackets or braces, sometimes, the use of larger parentheses will be observed.

Square brackets will always be used, to enclose or group several arithmetic operations that involve several simultaneous operations, as described in the example.

The bracket generally groups or implies that the most particular or small operations must be performed until finally breaking it down and thus solving the entire general operation.

Step-by-step explanation:

1. When there are no parentheses or square brackets, we do the multiplications and divisions first if there are any. If there are several positive and negative numbers we group them together and then add them together.

2. When there are parentheses, we first make the calculations for the parentheses if there are any, and then to remove the parentheses we apply the rule of signs, sign that is in front of the parenthesis for each sign that is inside.

3. When there are parentheses and square brackets, we make the parentheses first, we remove them applying the rule of signs. Then we make the brackets and remove them applying the rule of signs. Then we make the products and divisions and finally the sums.

answer: all of the odd numbers were opened

the first person was the one that was opening all of the lockers. since one is odd, this causes all of the odd number lockers to be opened in the end.

they used 313 gallons of paint