Download Literal Equations

Unit 2 Day 4 1/17/12
1. Turn in worksheet 2-2 and vocabulary definitions
2. Get calculator
3. Do bell ringer
Unit 2 Day 4: Bell ringer
In the empty boxes in each table, give two numbers that multiply
to be the bottom number and add to be the top number.
1 9
20
2.
9
18
3.
12
32
4.
3
-10
5.
-14
40
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Unit 2 test on Friday
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Homework: worksheet 2-2
Unit 2 Day 4 Notes
LITERAL EQUATIONS
(Literal equations are equations that have
multiple variables and you are asked to
solve for one of them)
1) Solve 2x - 4y = 7 for x
To get x by itself, what is the first step?
1.
2.
3.
4.
Add 2x
Subtract 2x
Add 4y
Subtract 4y
Answer Now
2) Solve 2x - 4y = 7 for y
To get y by itself, what is the first step?
1.
2.
3.
4.
Add 2x
Subtract 2x
Add 4y
Subtract 4y
Answer Now
D U
1.
2.
3.
4.
2) Solve 2x - 4y = 7 for y
- 2x
- 2x
Draw “the river”
-4y
=
7
2x
Subtract 2x from
both sides
-4
-4
Simplify
7  2x
Divide both sides
y
by -4
4
5. Does it simplify? Nope!
· -4 -2x
+2x ÷ -4
ya
3) Solve
 c for y.
3
What is the first step?
1.
2.
3.
4.
Multiply by 3
Divide by 3
Add a
Subtract a
Answer Now
D U
3) Solve for y:
1. Draw “the river”
2. Clear the fraction
– multiply both
sides by 3
3. Simplify
4. Subtract a from
both sides
5. Simplify
3
+a
ya
÷3
c
3
ya
c 3
3
y + a = 3c
-a -a
y = 3c - a
·3
-a
4) Solve for y: 4x – 2y = 12
1.
2.
3.
4.
-4x + 12
4x - 12
-2x + 6
2x - 6
Answer Now
D U
· -2 - 4x
+ 4x ÷ -2
1.
2.
3.
4.
4) Solve for y: 4x – 2y = 12
4x
4x
Draw “the river”
-2y = 12 – 4x
Subtract 4x from
both sides
-2
-2
Simplify
y = -6 + 2x
Divide both sides
by -2
or
y = 2x - 6
5. Does it simplify?
Yes!
5) The formula for the volume of a rectangular
prism is V = LWH. Which equation solves the
formula for L?
1. L = V - WH
VH
2. L
W
VW
3. L
H
4. L  V
HW
Answer Now
6) The formula for the volume of a pyramid
1
is V = bh . Which equation solves the
3
formula for h?
1. h = 3Vb
3b
2. h 
V
3V
3. h 
b
4. h  V
3b
Answer Now