Choose the best definition for the following term: exponent (1 point)   the number listed first when combining a variable and a number the number or value being raised to a power a letter that holds the place of some unknown value in mathematics shorthand that tells how many times the base is used as a factor, or how many times the base is multiplied by itself 3.  (01.02) simplify the following expression: 2x − 2y + 5z − 2x − y + 3z (1 point)   x − 3y + 8z 2x − 2y + 8z 3y + 8z −3y + 8z 4.  (01.02) evaluate the following expression using the values given: find 3x − y − 3z if x = −2, y = 1, and z = −2. (1 point)   −13 −1 1 13