Review Homework Page 163-165
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Transcript of Review Homework Page 163-165
Literal EquationsLiteral Equations
ANSWER 2a + 3 = 24
1. Write an equation for “3 more than twice a is 24.”
ANSWER 64 ft2
2. A square has a side length of 8 feet. Find the area ofthe square using the formula A = s2.
Review verbal equations
Literal Equations page 169Literal Equations page 169
1) Solve 2x - 4y = 7 for xTo get x by itself, what is the first step?
1. Add 2x2. Subtract 2x3. Add 4y4. Subtract 4y
1) Solve 2x - 4y = 7 for x
1. Draw the center line(whatever we do on one
side, we must do on the other)
2. Add 4y to both sides3. Simplify4. Divide both sides by 2
+ 4y = + 4y 2x = 7 + 4y 2 2
2) Solve 2x - 4y = 7 for yTo get y by itself, what is the first step?
1. Add 2x2. Subtract 2x3. Add 4y4. Subtract 4y
2) Solve 2x - 4y = 7 for y
1. Draw the center line
2. Subtract 2x from both sides
3. Simplify4. Divide both sides
by -4
- 2x = - 2x -4y = 7 - 2x -4 -4
3) Solve for y: 4x – 2y = 12
1. y = -4x + 122. y = 4x - 123. y = -2x + 64. y = 2x - 6
1. L = V - WH
2.
3.
4.
3) The formula for the volume of a rectangular prism is V = LWH. Which equation solves the
formula for L?
LV HW
LV W
H
LV
HW
1. h = 3Vb
2.
3.
4.
4) The formula for the volume of a pyramid is V = . Which equation solves the
formula for h?
13
bh
h 3bV
h 3Vb
h V3b
Subtract b from each side.
Write original equation.
Solve ax + b = c for x.STEP 1
SOLUTION
Solve ax + b = c for x. Then use the solution to solve 2x + 5 = 11. a = 2, b = 5, c = 11
Solve a literal equationEXAMPLE
xc – b
a=
ax + b = c
ax = c – b
Assume a 0. Divide each side by a.
The solution of 2x + 5 = 11 is 3.ANSWER
Simplify.
Substitute 2 for a, 5 for b, and 11 for c.
Solution of literal equation.
Use the solution to solve 2x + 5 = 11.STEP 2
Solve a literal equation
EXAMPLE
11 – 52=
x = c – b
a
= 3
PRACTICE
1. a – bx = c; 12 – 5x = –3
Solve the literal equation for x. Then use the solution to solve the specific equation
; 3ANSWER x = a – c
b
2. ax = bx + c; 11x = 6x + 20
; 4ANSWERc
x = a – b
Divide each side by 2.
Write original equation.
Write 3x + 2y = 8 so that y is a function of x. Solve for y.
EXAMPLE Rewrite an equation
Subtract 3x from each side.
3x + 2y = 8
2y = 8 – 3x
32
y = 4 – x
Multiply each side by 2.
Write original formula.
SOLUTION
Use the rewritten formula to find the height of the triangle shown, which has an area of 64.4 square meters.
b.
Solve the formula for the height h.a.
EXAMPLE 3 Solve and use a geometric formula
The area A of a triangle is given by the formula A = bh where b is the base and h is the height.
12
a. bh12A =
2A bh=
Substitute 64.4 for A and 14 for b.
Write rewritten formula.
Substitute 64.4 for A and 14 for b in the rewritten formula.
b.
Divide each side by b.
EXAMPLE 3 Solve and use a geometric formula
2A b h=
= 2(64.4) 14
= 9.2 Simplify.
ANSWER The height of the triangle is 9.2 meters.
h2A b=
PRACTICE
3. Write 5x + 4y = 20 so that y is a function of x.
54
y = 5 – x ANSWER
PRACTICE
The perimeter P of a rectangle is given by the formula P = 2l + 2w where l is the length and w is the width.
a. Solve the formula for the width w.
4 .
w = or w = – lP – 2l
2ANSWER P2
PRACTICE
Use the rewritten formula to find the width of the rectangle shown.
b .
2.4ANSWER
How toHow to
page 170
PracticePractice
Pages 171-173
HomeworkHomework