1. Algebra 1 Section 1.1 Evaluate algebraic expressions
A variable is a symbol (letter) used to represent a number.
x, y, z, Θ, φ, α
Variable (algebraic) Expression
x+ 2y z w

2. Evaluate the expression
To evaluate an algebraic expression
Substitute the value in the variable
Simplify the expression
6x when x = 12 6w + 4 when w = 8

3. Evaluate the expression.
3a + 2b when a = 5, b = 4, and c = -2 c

4. Formulas use variables
Simple Interest
I = P·r·t
I = interest P = principle
r = interest rate t = time
Find the simple interest on a principle of $2000 when invested at a rate of 6% per year for 3 years.

5. D =R·T Distance Formula
D=distance R=rate T=time
How far can you hike at a speed of 3 miles per hour in 2.5 hours?

6. Find the average speed of a car that travels 150 miles in 2.5 hours.
R = D T

7. Assignment
Page 6 Problems even, all, even