1. a) the product of 5 and a number x b) Evaluate when x = -1 2.a) 18 decreased by a number z b) Evaluate when z = a) the quotient of 16 and a number m b) Evaluate when m = a) the product of 8 and twice a number n b) Evaluate when n = 3 5. a) the sum of 3 times a number k and 4 b) Evaluate when k = -2

 Review how to evaluate variable expressions  Review what’s the difference between an expression and an equation?

 Expressions  8y, 16a/b, 4r + s, 7  Equations  3x + 4 = 6  3r = 9

 Variable = A letter or symbol that is used to represent a number  Evaluating an expression = Replacing all the variables in an expression with a number  Value of an expression = The result of the expression when you evaluate it.

Write the expression Substitute the values Simplify the expression

 5x + 4y  5(3) + 4(2)

 x + (2x -1)  3 + (2(3) - 1)

 In the expression 3x + 2, 3x and 2 are called terms of the expression.  In the expression 4x, 4 and x are called factors of the expression.  What’s the difference between a term and a factor?

 d = rt  d =(75)(1.5)  d =  So the distance traveled is miles