m + 4.6 = 9

1
Additional Examples 1A Solving Equations with
Decimals
Solve.
m 4.6 9
m 4.6 9
Since 4.6 is added to m, subtract 4.6 from both
sides to undo the addition.
2
Additional Examples 1B Solving Equations with
Decimals
Solve.
8.2p 32.8
Since p is multiplied by 8.2, divide both sides
by 8.2.
3
Additional Examples 1C Solving Equations with
Decimals
Solve.
Since x is divided by 1.2, multiply both sides by
1.2.
x 18
4
Check It Out! Example 1
Solve.
A.
m 9.1 3
Since 9.1 is added to m, subtract 9.1 from both
sides to undo the addition.
m 9.1 3
B.
5.5b 75.9
Since b is multiplied by 5.5, divide both sides
by 5.5.
5
Check It Out! Example 1C
Solve.
y 4.5
90
C.
Since y is divided by 4.5, multiply both sides by
4.5.
y 405
6
Additional Example 2A Solving Equations with
Fractions
Solve.
7
Additional Example 2B Solving Equations with
Fractions
Solve.
1 6
2 3
y


Find a common denominator, 6.
8
Additional Example 2C Solving Equations with
Fractions
Solve.
5 8
5 6
x

3
1
1
1
Multiply by the reciprocal. Simplify.
4
1
1
1
9
Check It Out! Example 2A
Solve.
1 9
5 9

n

Simplify.
10
Check It Out! Example 2B
Solve.

Find a common denominator, 4.
Simplify.
11
Check It Out! Example 2C
Solve.
3 8
3 4
x

1
1
1
2
Multiply by the reciprocal. Simplify.
1
1
1
1
x 2
12
Additional Example 3 Solving Word Problems Using
Equations
Janice has saved 21.40. This is of what she
needs to save to buy a new piece of software.
What is the total amount that Janice needs to
save?
Write an equation
Amount Saved
Amount Needed
1/3
?


21.40
a
?
13
Additional Example 3 Continued
Multiply by the reciprocal.
Simplify.
Janice needs to save 64.20.
14
Check It Out! Example 3
Write an equation
Capacity of minivans tank
Capacity of cars tank
2/3


g


15
Check It Out! Example 3 Continued
Multiply by the reciprocal.
Simplify.
The minivan can hold 36 gallons of gas.
16
Lesson Quiz
Solve.
x 41.1
1. x 23.3 17.8
2. j 14
4.

3. 9y
Tamara can mow acre in one hour. If her yard
is 2 acres, how many hours will it take her to
mow the entire yard?
5.
5 hours