Question 1 -4 : Write each algebraic expression in words in two ways.
1) x + 5
2) y - 9
3) 2 · m
4) a ÷ 6
5) Thomas reads 22 pages per hour. Write an expression for the number of pages he reads in m hours.
6) John is 2 years younger than Kay, who is k years old. Write an expression for John’s age
7) Peter runs a mile in 15 minutes. Write an expression for the number of miles that Peter runs in y minutes.
Questions 8-10 : Evaluate each expression for x = 7, y = 4, and z = 2.
8) x + y
9) y/z
10) xyz
11) Approximately ten 25-ounce plastic drink bottles must be recycled to produce 1 square foot of carpet.
a. Write an expression for the number of bottles needed to make x square feet of carpet.
b. Find the number of bottles needed to make 20, 50, and 200 square feet of carpet.
1. Answer :
The sum of x and 5.
x is increased by 5.
2. Answer :
The difference of y and 9.
9 less than y.
3. Answer :
2 times m.
The product of 2 and m.
4. Answer :
a divided by 6.
The quotient of a and 6.
5. Answer :
m represents the number of hours that Thomas reads.
Think : m groups of 25 pages.
25 · m or 25m
6. Answer :
k represents Kay's age.
Think : 'younger than' means 'less than'.
k - 2
7. Answer :
y represents the total time Peter runs.
Think : How many groups of 15 are in y.
y ÷ 15 or y/15
Evaluate each expression for x = 7, y = 4, and z = 2.
8. Answer :
x + y = 7 + 4
= 11
9. Answer :
y/z = 4/2
= 2
10. Answer :
xyz = 7 · 4 · 2
= 56
11. Answer :
a. The expression 10x models the number of bottles needed to make x square feet of carpet.
b. Evaluate 10x for x = 20, 50, and 200.
x = 20 ----> 10(20) = 200
x = 50 ----> 10(50) = 500
x = 200 ----> 10(200) = 2000
To make 20 ft^{2} of carpet, 200 bottles are needed.
To make 50 ft^{2} of carpet, 500 bottles are needed.
To make 200 ft^{2} of carpet, 2000 bottles are needed.
May 21, 24 08:51 PM
May 21, 24 08:51 AM
May 20, 24 10:45 PM