Download 1.4 Rewriting Equations

Friday Homework: begin weekly review
Ask your science teacher what formulas you are going to use in science this year (X- Credit)
1st: Put your homework and Corrections in the yellow folder
2nd: Take out planner, spiral, and math facts
3rd: Warm up: is a brief homework quiz- Take your time, go back over your steps
when you finish.
4th: After you finish warm up do math facts and set up Cornell Notes
1.4 Rewriting Equations
Essential Question:
What is a key step to solving for a specific variable?
Dress Code
Math Facts
Vocabulary:
Literal equations: An equation that has two or more
variables
A. Solve x + y = 15 for x.
x + y = 15
–y –y
x
= –y + 15
Locate x in the equation.
Since y is added to x, subtract y
from both sides to undo the
addition.
Solve for y:
Solve for y:
4.2𝑥 = .007𝑦 + .49
Solve for y:
Solve for y:
2π = 5y + 4
Monday Homework: 1.4 textbook pg. 30 #3, 6, 9, 10, 11, 12, 14, 16, 18, and 19
1st: Fill out planner. Take out spiral, and math facts.
2nd: Warm Up sheet in 2 squares. Do warm up first, then make corrections to Friday’s quiz on the BACK of your
warm up sheet.
3rd: After you finish warm up & quiz corrections, practice math facts.
SATELLITE TV: Provider A charges $75 for
installation and charges $39.95 per month for
the basic package. Provider B offers free
installation and charges $39.95 per month for
the basic package. Your neighbor subscribes
to Provider A the same month you subscribe
to Provider B. After how many months is your
neighbor’s total cost the same as your total
cost for satellite TV?
𝟏
− −𝟗𝒙 − 𝟔 = 𝟑𝒙 + 𝟐
𝟑
2nd, 5/6th, 7th hrs
The Plan for this week:
Monday: Finish lesson 1.4
Tuesday: Critical thinking activity
Wednesday: Review for Unit 1 test
Thursday: Review for Unit 1 test
Friday: Unit 1 test and spin for group points
4th hr
The Plan for this week:
Monday: Finish lesson 1.4
Tuesday: Review for Unit 1 test
Wednesday: Review for Unit 1 test
Thursday: Unit 1 test & critical thinking task
Friday: Survivor Lipsink contest during 4th hr & spin for
group points
Dress Code
Math Facts
3 minute timer
Last Week’s Challenge Answer
762-489=273
Thus a=6, b=9, c=2
Challenges of the Week
If a+1 = b+2 = c+3 = d+4 = a+b+c+d+5,
then a+b+c+d =??
&
Find formulas used in science and/or
business. Rewrite the formulas for two
different variables.
1.4 Rewriting Formulas
Essential Question: How can you use a
formula for measurement to write a formula
for a different measurement?
Science formulas?
A formula is an equation that states a rule for a relationship among
quantities.
In the formula d = rt, d is isolated. You can "rearrange" a formula to
isolate any variable by using inverse operations. This is called solving for
a variable.
Solving for a Variable
Step 1 Locate the variable you are asked to
solve for in the equation.
Step 2 Identify the operations on this variable
and the order in which they are applied.
Step 3 Use inverse operations to undo
operations and isolate the variable.
Solve pq = x for q.
pq = x
Locate q in the equation.
Since q is multiplied by p, divide
both sides by p to undo the
multiplication.
The formula for an object’s final velocity is f = i – gt, where
i is the object’s initial velocity, g is acceleration due to
gravity, and t is time.
Solve for i.
f = i – gt
f = i – gt
+ gt
+gt
f + gt = i
Locate i in the equation.
Since gt is subtracted from i,
add gt to both sides to undo
the subtraction.
What Do You Think?
Solve 5 – b = 2t for t.
5 – b = 2t
Locate t in the equation.
Since t is multiplied by 2, divide
both sides by 2 to undo the
multiplication.
Your Turn:
Solve the formula d = rt for t. Find the time in hours that it would take
Ernst Van Dyk to travel 26.2 miles if his average speed was 18 miles per
hour.
d = rt
Locate t in the equation.
Since t is multiplied by r, divide both
sides by r to undo the multiplication.
Now use this formula and the information given in the problem.
Van Dyk’s time was about 1.46 hours.
The formula for the area of a triangle is
A=
bh,
where b is the length of the base, and h is the height. Solve for h.
A=
bh
2A = bh
Locate h in the equation.
Since bh is multiplied by , divide both
sides by to undo the multiplication.
Since h is multiplied by b, divide both sides by b to undo the
multiplication.
Solve
for V
Locate V in the equation.
VD = m
Since m is divided by V, multiply
both sides by V to undo the
division.
Since V is multiplied by D, divide
both sides by D to undo the
multiplication.
The formula C = d gives the circumference of a circle C in terms of
diameter d. The circumference of a bowl is 18 inches. What is the
bowl's diameter? Leave the symbol  in your answer.
Locate d in the equation.
Since d is multiplied by , divide both
sides by  to undo the multiplication.
Now use this formula and the information given in the problem.
Now use this formula and the information given in
the problem.
The bowl's diameter is
inches.
Draw a horizontal line across the bottom of
today’s notes
Summarize today’s lesson.
Describe how to solve for r in the equation d = rt
Your turn: white Boards
Solve for the indicated variable.
1.
for h
2. P = R – C for C
C=R–P
3. 2x + 7y = 14 for y
4.
for m
5.
for C
m = x(k – 6 )
C = Rt + S
Part 2
Euler’s formula, V – E + F = 2, relates the number
of vertices V, the number of edges E, and the
number of faces F of a polyhedron.
Solve Euler’s formula for F.
F=2–V+E
How many faces does a polyhedron with 8 vertices
and 12 edges have?
6