Transcript Solving Two-Step Equations(2-2).

COURSE 3 LESSON 2-2
Solving Two-Step Equations
Solve 4p + 7 = –13.
4p + 7 = –13
4p + 7 – 7 = –13 – 7
Subtract 7 from each side.
4p = –20
Simplify.
4p
–20
=
4
4
Divide each side by 4.
p = –5
Simplify.
Check 4p + 7 = –13
4(–5) + 7
–13
–13 = –13
Substitute –5 for p.
The solution checks.
2-2
COURSE 3 LESSON 2-2
Solving Two-Step Equations
Solve 7 = x – 1.
5
x
7+1= 5 –1+1
x
8= 5
Simplify.
x
(5)(8) = (5) 5
40 = x
Add 1 to each side.
Multiply each side by 5.
Simplify.
2-2
COURSE 3 LESSON 2-2
Solving Two-Step Equations
Six people at dinner shared equally a total bill of $180.
This total included a tip of $30. Write and solve an equation to find
the amount of each person’s share for dinner without the tip.
Words (each person’s share for dinner  6) plus tip is $180
Let s = each person’s share for dinner.
Equation
6s
+
30 =
6s + 30 = 180
6s + 30 – 30 = 180 – 30
Subtract 30 from each side.
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180
COURSE 3 LESSON 2-2
Solving Two-Step Equations
(continued)
6s = 150
Simplify.
150
6s
=
6
6
Divide each side by 6.
s = 25
Simplify.
Each person’s share for dinner, without the tip, is $25.
2-2
COURSE 3 LESSON 2-2
Solving Two-Step Equations
Solve each equation.
1.
n
– 14 = 1
3
45
2. 16 – 2x = 9
3.5
Write and solve an equation.
3. Suppose you bought a $2.75 sandwich and two drinks of
equal price. You spend $4.25 in all. How much does one drink cost?
2d + 2.75 = 4.25; $.75
2-2