These are symbals used to group numbers together

Parenthesis, Brackets and Braces

Step-by-step explanation:

All three are used to group numbers together in mathematical equations.

Parenthesis ( ) are the most common, but Brackets [ ] and Braces { } are sometimes used as well.

pakistan's principal natural resources are arable land and water. about 25% of pakistan's agriculture accounts for about 21% [1] of gdp and employs about 43% of the labour force. in pakistan, the most agricultural province is punjab where wheat and cotton are the most grown.

this may not be at all, but i use the same website you're using for school, and if i'm stuck doing one of these i try to look for it on the section.