This document defines variables, coefficients, and constants in algebra and provides examples of each. It then lists 3 practice problems asking the reader to identify the variables, coefficients, and constants in each expression: 1) 5x + 7 has variable x, coefficient 5, and constant 7. 2) 6x + 9 has variable x, coefficient 6, and constant 9. 3) 9x + 2 has variable x, coefficient 9, and constant 2.