1-6 Writing Expression (pgs 29-32) 1-9 Using formulas (pgs 40-43)

1
1-6 Writing Expression (pgs 29-32)1-9 Using
formulas (pgs 40-43)

• 9P3Describe problems using symbolic
  representation

2

• What is the difference between an equation and an
  expression???
• Expressions
• combination of variables, numbers, and
  operations.
• can be simplified by combining like terms
• (ex 2xy 4x 3 or 2a 3a)
• Equations
• two expressions that are equal.
• Both sides have the same value.
• Can be solved to find the value that works( most
  equations only have one number that makes them
  true.
• (ex 2x 3 4x 5) ? x -1 no other number
  works

3

• Things to note
• Watch subtraction problems x - 2 is different
  than 2 x
• Remember your vocabulary (What words mean -
  )
• Put the equal sign in the equation where you see
  the word is (or other forms such as has, had,
  was, were, etc.. )

4
Which words/symbols mean -
-
plus and added to   greater than more than increased by total Sum minus difference from less less than fewer than decreased by take away - times product at double, triple, etc. twice of (fractions ) ( ) ab quotient of goes into per divided by a a/b
b
5

• Write an expression for the following
• 1) The sum of a number and 3
• n 3
• 2) three less than twice a number
• 2n - 3
• 3) 2 times the sum of 8 and a number
• 2(n8)
• 4) Let s be Sues age. If Sue is 10 years older
  than Roy, write an expression for Roys age
• s - 10

6
Use formula to solve problems

• The speed of an airplane (a) is the Mach number
  (M) times the speed of sound (s).
• What equation represents this relationship?
• aMs
• If an airplane is traveling at Mach 1.5 and
  the speed of sound is 720mi/hr, what is the speed
  of the airplane?
• Step 1 write formula a Ms
  
• Step 2 Substitute a
  1.5720mi/hr
• Step 3 simplify/label units a 1080 mi/hr

7
Assignment

• 1-6/30/ 2-48eoe, 62-72 e
• 1-9/42-43/ 2-22e, 26-34e

8
Marker board

• Pg 30
• 3
• 23
• 25
• 31
• 39
• 43
• 45
• 67
• 71
• Pg 42
• 3
• 13
• 17
• 27