News & Notes
1. Perimeter of a Square: 2. Area of a Square:
P = 4S
The area of a square is actually the
same as the area of a rectangle: LxW
However, since the lengths of the sides are
the same, you are multiplying a number by
itself. So, the formula for the area of a square
is:
A = S2
Formulas
Solving Equations with Variables on Both Sides
When an equation has variables on both sides, three
different results are possible.
Write & solve this equation: 2x + 2 = 4 + x
The equation results in a solution of a single number.
In this case, x = 2
a. Most of the equations we solve are conditional equations
A 2nd
Possibility
 3x - 9 = 3x + 10
 A linear equation has NO SOLUTION when the solved
equation has no variable and the equation is false.
3x - 3x = no variable, -9 = 10
a) Known as Contradiction Equations
1. If variables cancel and constants are not equal, there
are no possible solutions.
2. When solving these types of problems, write No
Solution on your paper.
A 3rd
Possibility
 When an equation has variables on both sides ,something
else may occur. Solve the equation: 4(x – 5) = 4x - 20
4x -20 = 4x -20; Subtract 4x from the left side and -20 = -20
These are called identity equations. It means ALL REAL
NUMBERS make the sentence true.
A linear equation is an identity when the solved equation
has NO VARIABLE and the solution is TRUE!
In other words, no matter what number we substitute for
x, the equation will be true.
2. When solving these types of problems, write Infinite
Solutions on your paper.
Therefore…
• When solving equations with variables on both
sides, 3 different things can happen.
1) solution is a single number (x = 4) (conditional)
2) solution is NO SOLUTION (Contradiction)
3) solution is ALL REAL Numbers ( IDENTITY)
Translating
Translating
A certain number, which first has 15 subtracted from it, then
has the difference multiplied by 7, will give a result of 28.
What’s the number? 7(x – 15) = 28 7x – 105 = 28
7x = 133; x = 19
Tell me the easier way to solve this
equation
x – 15 =
𝟐𝟖
𝟕
x – 15 = 4; x = 19
Be flexible, follow the path of least
resistance.
Translating
1. Jane is nine years older than Marie. Jane is four
times as old as Marie. How old are each of the girls?
2. The sum of three consecutive odd numbers is 87.
What are the numbers?
Translating & Solving Word Problems
3. As the head pastry chef, you make $7.00/hr. So far you
have earned $42.00. Which of the following equations is
the algebraic model for this situation?
A. What does the variable represent?
B. What is the constant?
Let’s put all the algebra we’ve
learned so far to solve this:
2x + 1
2x + 1
xx
Perimeter =
50 ft.
Find the dimensions
of the rectangle?
(How long is the L & W)
The dimensions are: W = L =8 17
Writing & Interpreting Decimals

October 21, 2015

  • 2.
  • 3.
    1. Perimeter ofa Square: 2. Area of a Square: P = 4S The area of a square is actually the same as the area of a rectangle: LxW However, since the lengths of the sides are the same, you are multiplying a number by itself. So, the formula for the area of a square is: A = S2 Formulas
  • 4.
    Solving Equations withVariables on Both Sides When an equation has variables on both sides, three different results are possible. Write & solve this equation: 2x + 2 = 4 + x The equation results in a solution of a single number. In this case, x = 2 a. Most of the equations we solve are conditional equations
  • 5.
    A 2nd Possibility  3x- 9 = 3x + 10  A linear equation has NO SOLUTION when the solved equation has no variable and the equation is false. 3x - 3x = no variable, -9 = 10 a) Known as Contradiction Equations 1. If variables cancel and constants are not equal, there are no possible solutions. 2. When solving these types of problems, write No Solution on your paper.
  • 6.
    A 3rd Possibility  Whenan equation has variables on both sides ,something else may occur. Solve the equation: 4(x – 5) = 4x - 20 4x -20 = 4x -20; Subtract 4x from the left side and -20 = -20 These are called identity equations. It means ALL REAL NUMBERS make the sentence true. A linear equation is an identity when the solved equation has NO VARIABLE and the solution is TRUE! In other words, no matter what number we substitute for x, the equation will be true. 2. When solving these types of problems, write Infinite Solutions on your paper.
  • 7.
    Therefore… • When solvingequations with variables on both sides, 3 different things can happen. 1) solution is a single number (x = 4) (conditional) 2) solution is NO SOLUTION (Contradiction) 3) solution is ALL REAL Numbers ( IDENTITY)
  • 8.
  • 9.
  • 10.
    A certain number,which first has 15 subtracted from it, then has the difference multiplied by 7, will give a result of 28. What’s the number? 7(x – 15) = 28 7x – 105 = 28 7x = 133; x = 19 Tell me the easier way to solve this equation x – 15 = 𝟐𝟖 𝟕 x – 15 = 4; x = 19 Be flexible, follow the path of least resistance. Translating
  • 11.
    1. Jane isnine years older than Marie. Jane is four times as old as Marie. How old are each of the girls? 2. The sum of three consecutive odd numbers is 87. What are the numbers? Translating & Solving Word Problems 3. As the head pastry chef, you make $7.00/hr. So far you have earned $42.00. Which of the following equations is the algebraic model for this situation? A. What does the variable represent? B. What is the constant?
  • 12.
    Let’s put allthe algebra we’ve learned so far to solve this: 2x + 1 2x + 1 xx Perimeter = 50 ft. Find the dimensions of the rectangle? (How long is the L & W) The dimensions are: W = L =8 17
  • 13.