Page 155 - Algebra 1

L E S S O N Solving Decimal Equations 24
Warm Up
1. Vocabulary If 103 = 1,000, then 1,000 is the third of 10.
(3)
A exponent B base C power D factor 2. Write the numbers below in order from least to greatest.
(SB 1)
3. Simplify 4x - 3x2 + 7x. (16)
-2.85, _5 , 0.58, -0.8 8
New Concepts To write decimals as integers, multiply by a power of 10. Solving by Multiplying by a Power of 10
Example
1
Solve.
a. 8+0.5x=10.5 SOLUTION
8 + 0.5x = 10.5 10(8) + 10(0.5)x = 10(10.5)
Multiply each term by 10. Multiply.
Subtraction Property of Equality Simplify.
Division Property of Equality Simplify.
Multiply each term by 1,000. Multiply.
Subtraction Property of Equality Simplify.
Division Property of Equality Simplify.
80 + 5x = 105
-_ 8_0
-_ 8_0
5x = 25
5x = 25 __
55 x=5
Hint
If the decimals are
in the thousandths, hundredths, and tenths places, multiply by a power of 10 that will make the decimal with the least value an integer.
0.006 × 1000 = 6
b. 0.006a + 0.02 = 0.2 SOLUTION
0.006a + 0.02 1000(0.006a) + 1000(0.02) 6a+20 -_ 2_0 6a
= 0.2
= 1000(0.2) = 200
-_ 2_0
= 180
Online Connection www.SaxonMathResources.com
6a=180 __
66 x = 30
140 Saxon Algebra 1