6th Grade Math Textbook, Progress

Two-Step Equations

14-1

Mario ordered two large plain pizzas for delivery

and paid a total of $21, including a $3 tip.

How much did each pizza cost?

To find how much, write and solve a two-step equation.

A two-step equation involves two operations.

Let prepresent the cost of one pizza.

2 p
$3$3$21$3

2 p$18

2 p 2 $18 2

p$9

Check: 2 p
$3$21 2 $9
$3
$21

$21$21 True

Each pizza cost $9.

Study these examples.

Solve: 
1.2 8.2

1.2 1.28.2 1.2

 7

• 7  7 • 7

x 49

Check: 
1.2
8.2

8.28.2 True

49

7

x

7

x

7

x

7

x

7 Solve: 2.4 27.6

2.4 
2.427.6 
2.4

 30

• n 30 • n

60  30 n

60  30  30 n 30

2 n

Check: 2.4
27.6

27.627.6 True

60

2

60

n

60

n

60

n

60

n

cost of 2 pizzas plus tip equals total cost

2 p 
 $3  $21

Subract $3 from both sides.

Simplify.

Divide both sides by 2.

solution

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 Substitute $9 for p.

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$0 p 2 p $21

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