The structure on the left does not have any resonance contributors in which electrons are. donated to the carbon with the open octet. Compare this with the carbocation that has. resonance and a delocalized positive charge. Charge delocalization imparts stability, so. the structure with resonance is lower in energy.
A numerical expression is a mathematical sentence involving only numbers and one or more operation symbols. Examples of operation symbols are the ones for addition, subtraction, multiplication, and division. They can also be the radical symbol (the square root symbol) or the absolute value symbol.
Both use numbers and variables; however it is all based on the arrangement. So let's take look at both to determine their use and relationship. An expression is a combination of numbers, variables, and symbols to be calculated. An equation contains expressions that are separated by an equals sign. A further look at the mathematical expression can be explained with numbers and variables such as: 7x + y - 4.