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Algebra IA – Chapter 2
Problems for Today
1
2
3
4
5
6
7
8
9 10
11 12 13 14 15
Solve and check your answer.
1
1.8  n  3
1.8  n  3
1.8  1.8  n  3  1.8
n  1.2
2-1: Solve one-step equations in one variable
by using addition or subtraction.
Check.
1.8  1.2  3
33
2
Solve and check your answer.
w
2 
7
w
2 
7
w
(7)(2) 
(7)
7
14  w
2-2: Solve one-step equations in one variable by
using multiplication or division.
Check.
14
2 
7
2  2
Solve and check your answer.
a
15   2
3
a
15   2
3
a
15  2   2  2
3
a
(3)17  (3)
3
51  a
Check.
51
15   2
3
15  17  2
15  15
2-3: Solve equations in one variable that contain
more than one operation.
3
Solve.
2 x  1  x  11
2 x  1  x  11
2 x  x  1  x  x  11
x  1  11
x  1  1  11  1
x  12
2-4: Solve equations in one variable that contain
variable terms on both sides.
4
The formula for the volume of a rectangular
prism with length l, width w, and height h is:
V  lwh Solve the formula for w.
V  lwh
V lwh

lh
lh
V
w
lh
2-5: Solve a formula for a given variable.
5
Solve for s.
st  3t  6
st  3t  3t  6  3t
st 6  3t

t
t
6  3t
s
t
2-5: Solve an equation in two or more
variables for one of the variables.
6
Find the unit rate.
A computer’s fan rotates 2000 times in 40 seconds.
2000 rotations
40 seconds
 50 rotations/second
2-6: Write and use ratios, rates, and unit rates.
7
Solve the proportion.
10 52

h 13
10 52

h 13
10(13)  52 h
130  52 h
130 52 h

52
52
2.5  h
2-6: Write and solve proportions.
8
Find the value of x in the diagram.
8 x

4 2
4 x  8(2)
4 x  16
4 x 16

4
4
x4
2-7: Use proportions to solve problems involving geometric figures.
9
Roger is 5 feet tall and casts a shadow 3.5 feet long.
At the same time, the flagpole outside his school
casts and shadow 14 feet long. Write and solve a
proportion to find the height of the flagpole.
5 3.5

x 14
3.5 x  5(14)
3.5 x  70
3.5 x 70

3.5 3.5
x  20
10
The flagpole is 20 feet tall.
2-7: Use proportions and similar figures to measure objects indirectly.
Find the value. Round to the nearest tenth if necessary.
Find 75% of 40.
75%  0.75
0.75(40)
 30
2-8: Solve problems involving percents.
11
A sales representative earns a 2.5%
commission on sales. Find the commission
earned when the total sales are $80,700.
2.5%  0.025
0.025(80700)
 2017.5
The commission earned
on $80,700 is $2,017.50
2-9: Use common applications of percents.
12
13
Estimate a 15% tip on a $42.65 restaurant bill.
10% of $42.65 is $4.265
5% is half of $4.265 which is about $2.13
15% is 10% + 5%
$4.27 + $2.13 = $6.40
A 15% tip on $42.65 is about $6.40.
2-9: Estimate with percents.
Find the percent change. State whether it is a percent
increase or decrease.
25 to 45
Amount of change
-----------------------Original amount
20
 0.8
25
80%
The change is an 80% increase.
2-10: Find percent increase and decrease.
14
What is the final price on a $185 leather jacket that
is on sale for 40% off?
100%  40%  60%
60%  0.6
0.6(185)
15
The final price of the jacket
on sale for 40% off is $111.
 111
2-10: Find percent increase and decrease.