Warm-Up2Exercises
EXAMPLE
Rewrite an equation
Write 3x + 2y = 8 so that y is a function of x.
3x + 2y = 8
2y = 8 – 3x
y = 4 – 3x
2
Write original equation.
Subtract 3x from each side.
Divide each side by 2.
Warm-Up
Exercises
GUIDED
PRACTICE
3.
for Examples 2 and 3
Write 5x + 4y = 20 so that y is a function of x.
ANSWER
y = 5 – 5x
4
Warm-Up
Exercises
GUIDED
PRACTICE
4.
for Examples 2 and 3
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.
ANSWER
w=
P – 2l
2
or w =
P
–l
2
Warm-Up4Exercises
EXAMPLE
Solve a multi-step problem
Temperature
You are visiting Toronto, Canada, over the weekend.
A website gives the forecast shown. Find the low
temperatures for Saturday and Sunday in degrees
5
Fahrenheit. Use the formula C = (F – 32) where C is
9
the temperature in degrees Celsius and F is the
temperature in degrees Fahrenheit.
Warm-Up4Exercises
EXAMPLE
Solve a multi-step problem
SOLUTION
STEP 1 Rewrite the formula. In the problem, degrees
Celsius are given and degrees Fahrenheit
need to be calculated. The calculations will be
easier if the formula is written so that F is a
function of C.
5
C = 9 (F – 32)
Write original formula.
9 5
9
C = · (F – 32)
5 9
5
9
C = F – 32
5
9
C + 32 = F
5
9
Multiply each side by , the
5
reciprocal of 5 .
9
Simplify.
Add 32 to each side.
Warm-Up4Exercises
EXAMPLE
Solve a multi-step problem
ANSWER
9
The rewritten formula is F = C + 32.
5
Daily
Homework
Quiz
Warm-Up
Exercises
1.
Write the equation 15 = 5y – 4x so that y is a
function of x.
ANSWER
2.
Solve C = 2pr for r.
ANSWER
3.
y= 4 x+3
5
r=
C
p
2
Solve V = 1 Bh for B.
3
ANSWER
B = 3V
h
Warm-Up Exercises
Extra Practice
Solve for the given variable.
1) 𝐹 = 𝑉0 𝑡 + 𝑑 𝑎 − 𝑎0 , 𝑓𝑜𝑟 𝑎
𝐹 − 𝑉0 𝑡
𝑎=
+ 𝑎0
𝑑
2) 𝑎 + 𝑏 = 𝑥𝑦𝑧, for y
𝑎+𝑏
𝑦=
𝑥𝑧
3) 𝑙 = 𝑎 𝑏 + 𝑐 , 𝑓𝑜𝑟 𝑎
𝑙
𝑎=
𝑏+𝑐