Download ALGEBRAIC EXPRESSION - Siuslaw School District

LESSON – ALGEBRAIC EXPRESSIONS
[TEXT: LESSON 1-3]
ALGEBRAIC EXPRESSION – A mathematical statement that contains one or more variables
Examples: 3n + 8,
3(2x + 5),
Examples/Practice: Write an algebraic expression that models each situation. Use the algebraic
expression to answer each set of questions.
1) You have $150, but you are spending $2 each
day for school lunch. Write an algebraic
expression to represent the amount of money
you will have remaining after d days.
2) Joe has $100. He earns $12 an hour. Write an
algebraic expression to model the amount of
of money Joe has after working x hours.
a) How much money will you have after 17 days? a) How much money will Joe have after working a
40 hour week?
b) How much money will you have after 45 days? b) How much money will Joe have after working
15 hours?
c) In how many days will you have no money
left?
c) Joe has been saving to purchase a new laptop
computer that costs $1450. How many hours
must he work to have enough money to purchase
computer?
Examples: Write an algebraic expression that models the given word phrase.
3) 4 more than twice a number n
4) sum of numbers a and b divided by 2
5) half the difference of a number n and 5
6) quotient of the sum of a number x and 5
and twice the number y
EVALUATE AN ALGEBRAIC EXPRESSION – To evaluate an algebraic expression, substitute a
number for each variable in the expression. Then simplify using the order of operations.
Examples: Evaluate each algebraic expression for the given values of the variable.
8) 2x3 – 5x for x = 3
9)
for a = 9 and b = –2
10)
for x = 7 and y = 4
ASSIGNMENT
LESSON 1-3: ALGEBRAIC EXPRESSIONS
For 1 & 2: Write an algebraic expression that models each situation. Use the algebraic expression to
answer each set of questions.
1) A water storage tank contains 240 gallons of
water. Each day the tank loses 2.5 gallons of
water due to a small pin hole leak at the bottom
of the tank. Write an algebraic expression that
models the amount of water remaining in the
tank after d days have passed.
2) A small swimming pool is being filled with water.
Initially, the pool contained 3000 gallons of water.
Water is being pumped into the pool at a rate of
10 gallons per minute. Write an algebraic expression
that models the amount of water in the pool after
m minutes.
a) How much water remains in the tank after
40 days?
a) How much water is in the pool after 110 minutes
of pumping water into the pool?
b) How much water remains in the tank after
100 days?
b) How much water is in the pool after 4 hours of
pumping water into the pool?
c) In how many days will the tank be empty?
c) When full the pool contains approximately 7000
gallons. How many minutes will it take to fill
the pool?
For 3-6: Write an algebraic expression that models the given word phrase.
3) seven fewer than twice a number n
4) two times the sum of a and b
5) nine more than the product of 5 and a
number x
6) quotient of 4 more than the number x and the
number y decreased by 3
For 7-10: Evaluate each algebraic expression for the given values of the variable.
7) 7(a + 4) + 3b – 8 for a = –4 and b = 5
9)
for x = 6 and y = –3
8) 3x2 – 5x + 2
10)
for x = –2
+ y2 for x = –8 and y = 5
ALGEBRA 2 WARM-UPS (After Lesson 1-3)
1) Suzzanah walks after school each day.
2) The Siuslaw Booster Club is having a
She has walked a total of 35 miles and plans
membership drive. They currently have 25
to continue to walk 3 miles each day thereafter.
members and have a goal of recruiting 5 new
Write an algebraic expression that models
members per week. Write an algebraic expression
the distance traveled after d days.
that models the total number of members after
w weeks of recruitment.
a) How far (total) will she have walked after
14 days?
6 weeks?
a) How many members do they hope to have in
10 weeks?
25 weeks?
b) How many days will she have to walk to
reach a total of 200 miles?
b) If the club’s goal is to have at least 200 members,
in how many weeks will they reach this goal?