Solving One Step Equations

1
Solving One Step Equations

• 2.1
• Learn how to write and solve equations so we can
  solve real world problems about distance, rate,
  time and more

2
Inverse Operations

• To solve an equation you need to isolate your
  variable.
• To do this you use inverse operations
• and are inverse operations because they undo
  each other
• and / are also inverse operations for the same
  reason

3
Set up

• 1) Equation
• Mathematical sentence that states two numbers or
  expressions are true
• 2) Isolate the variable
• Do so by using inverse operations
• 3) Solve for your variable

4
Example

• Mr. Chances black lab
• How much does Rocky weigh?
• When Mr. Chance weighs himself the scale reads
  197 pounds.
• When he holds his dog and weighs them together
  the scale reads 286 pounds.
• So we let x Rockys weight
• So 197 x 286
• Now we must isolate the variable.How?

5

• 197 x 286
• This is a positive 197 so we subtract 197 from
  BOTH sides
• 197 -197 x 286 197
• This leaves us with
• x 286 -197 or x 89
• So Rocky weighs 89 pounds
• What a Fat dog!

6

• Example
• t/60 12.5
• To undo division we ?
• Multiply and remember what we do to one we have
  to do to the other
• Sot/6060 12.560
• 60/60 t 12.5 60
• t 750

7
Example

• -x 13 9
• So to undo subtraction we add
• -x -13 13 9 13
• what we do to one side we to do the other
• Now we have x 22
• To isolate x we multiply both sides by -1 and we
  get
• x -22

8
On your Own

• In 1992 Hwang Young-jo from South Korea won the
  Marathon in the Olympics in 133 minutes. The
  distance is the same as the Boston Marathon (26.2
  miles). Find his average speed or rate in miles
  per minute. (drt)

9
Olympics Cont

• We know distance rate (time)
• So The distance is 26.2 and the time is 133.
• Therefore 26.2 r 133
• To isolate r we divide both sides by 133
• 26.2/133 r
• R .2 miles per minute

10
Homework

• P. 58
• 1-18, 24-29