Page 149 - Algebra 1

L E S S O N Solving Two-Step Equations 23
Warm Up
1. Vocabulary In the equation -5x = 20, -5 is the
(2)
(variable, coefficient). Simplify.
2. 3(x - 4) (15)
3. -2(x - 3) + 4(x + 1) (18)
4. Evaluate _3 n + _5 for n = _2 . (9) 469
5. Multiple Choice
What is the solution of -7 + x = 14?
(19)
A -2 B2 C7 D 21
New Concepts If an equation has two operations, use inverse operations and work backward to undo each operation one at a time.
To reverse the order of operations: • First add or subtract.
• Then multiply or divide.
Evaluating Expressions and Solving Equations
a. Evaluate 3x - 2 for x = 4.
SOLUTION Substitute 4 for x and use the order of operations.
3(4) - 2 Multiply first. 12 - 2 = 10 Then subtract.
b. Solve3x-2=10.
SOLUTION Reverse the order of operations. 3x - 2 = 10
Example
1
Online Connection www.SaxonMathResources.com
+_ _2 = +_ _2
3x = 12
3x = 12 __
33 x=4
Undo the subtraction by adding.
Undo the multiplication by dividing.
134 Saxon Algebra 1