One meaning of the word evaluate is to find the value of an expression. to evaluate, replace a variable with a number and calculate the result. for example, when you are asked to evaluate the expression 4x ? 2 when x = ? 7, you would put ? 7 in place of the variable and calculate: 4 · (? 7) ? 2 = ? 30. evaluate the expressions below for the given values of x and y. homework ? 6/x + 9 if x = 3 8x ? 3 + y if x = 2 and y = 1 2xy if x = 5 and y = ? 3 2x2 ? y if x = 3 and y = 8