She looked at him curiously - at his ugly tweed suit, his yellow boots, and up into the strong, forceful face with eyes set in deep hollows under his protruding brows, at the heavy jaws giving a certain coarseness to his expression, which his mouth and forehead, well-shaped though they were, could not altogether dispel.
Definition of Expression. An Expression is a mathematical phrase that combines numbers and/or variables using mathematical operations. An expression is a representation of a value; for example, variables and/or numerals that appear alone or in combination with operators are expressions.
Equation. in mathematics, a statement, usually written in symbols, that states the equality of two quantities or algebraic expressions, e.g., x +3=5. The quantity x +3, to the left of the equals sign (=), is called the left-hand, or first, member of the equation, that to the right (5) the right-hand, or second, member.