Solving Equations With Variables on Both Sides

1
Solving Equations With Variables on Both Sides
PRE-ALGEBRA LESSON 7-5
(For help, go to Lesson 7-2.)
Solve each equation. 1. k 3k 20 2. 8x
3x 35 3. 3b 2 b 18 4. 8 y 7y
40
Check Skills Youll Need
7-5
2
Solving Equations With Variables on Both Sides
PRE-ALGEBRA LESSON 7-5
7-5
3
Solving Equations With Variables on Both Sides
PRE-ALGEBRA LESSON 7-5
Solve 4c 3 15 2c.
4c 3 15 2c
Quick Check
7-5
4
Solving Equations With Variables on Both Sides
PRE-ALGEBRA LESSON 7-5
Steve types at a rate of 15 words/min and Jenny
types at a rate of 20 words/min. Steve and Jenny
are both typing the same document, and Steve
starts 5 min before Jenny. How long will it take
Jenny to catch up with Steve?
words Jenny types words Steve types
7-5
5
Solving Equations With Variables on Both Sides
PRE-ALGEBRA LESSON 7-5
(continued)
20x 15(x 5)
Jenny will catch up with Steve in 15 min.
7-5
6
Solving Equations With Variables on Both Sides
PRE-ALGEBRA LESSON 7-5
(continued)
Check   Test the result. At 20 words/min for 15
min, Jenny types 300 words. Steves time is five
min longer. He types for 20 min. At 15 words/min
for 20 min, Steve types 300 words. Since Jenny
and Steve each type 300 words, the answer checks.
Quick Check
7-5
7
Solving Equations With Variables on Both Sides
PRE-ALGEBRA LESSON 7-5
Solve each equation. 1. 3 2t 7t 4 2. 18
6z 4z 3. 2q 4 5 5q 4. 7(v 4)
3(3 v) 1 5. You work for a delivery
service. With Plan A, you can earn 5 per hour
plus .75 per delivery. With Plan B, you can earn
7 per hour plus .25 per delivery. How many
deliveries must you make per hour to earn the
same amount from either plan?
9
3
9
4 deliveries
7-5