Page 179 - Algebra 1

L E S S O N Solving Equations with Variables
28
on Both Sides
Warm Up
1. Vocabulary In the expression -5x + 2 + 3x, -5x and 3x are
(2)
terms.
2. Simplify 10 - 4(5 + 3) + 23.
(7)
Solve.
3. 2(3 - x) = 10
(26)
4. -3(1 + 2x) + x = 32 (26)
5. Multiple Choice Which value is a solution to the equation
3(x - 4) - x = 30?
A 14 B 9 C 6 D 21
New Concepts To solve an equation with variables on both sides, use inverse operations to bring the variables together on one side of the equation.
Materials
• algebra tiles
Exploration Modeling Variables on Both Sides of an Equation Use algebra tiles to model and solve 4x + 5 = 2x + 11.
4x + 5
2x + 11
xxxx
+++ ++
xx
+++++ +++++ +
Model each side of the equation.
Add 2 -x-tiles to both sides. Remove pairs that equal zero.
xxxx
-x -x
+++ ++
+++++ +++++
+ -x -x
xx
xx+++++ -----
++++++ +++++ -----
Add 5 -1-tiles to both sides. Remove the zero pairs.
xx
++ ++ ++
Arrange into 2 equal groups.
What is the value of x?
Online Connection www.SaxonMathResources.com
a. Model x + 3 = 2x - 4. Then find the value of x. b. Model 3x - 1 = x - 3. Then find the value of x.
164 Saxon Algebra 1