Download Solving Multi-Step Equations

3.3 Solving Multi-Step Equations
GOAL
1
USING TWO OR MORE
TRANSFORMATIONS
SOLVING MULTI-STEP EQUATIONS
1. Simplify each side of the equation first.
2. Perform inverse operations in reverse order.
EXAMPLE 1
Extra Example 1
Solve:
1
x  5  10
2
Click to see the solution
EXAMPLE 2
Extra Example 2
Solve:
2x – 9x + 17 = –4
Click to see the solution
Checkpoint
Solve
2
1
x  x  9  1
5
5
x = –50
EXAMPLE 3
Extra Example 3
Solve
4x + 12(x – 3) = 28
Click to see the solution
EXAMPLE 4
Extra Example 4
Solve
2x – 5(x – 9) = 27
Click to see the solution
Checkpoint
Solve
10x – 6(2x + 5) = 20
x = –25
EXAMPLE 5
Extra Example 5
Solve
3
12 
 x  2
10
Click to see the solution
Checkpoint
Solve
4
24   x  7 
3
x = –11
3.3 Solving Multi-Step Equations
GOAL
2
SOLVING REAL-LIFE PROBLEMS
We will look at some specific real-life problems to learn
how to write multi-step equations which can then be
solved.
EXAMPLE 6
Extra Example 6
What Celsius temperature would indicate a fever of 104°F?
9
Use the formula F  C  32.
5
Click to see the solution
Checkpoint
Use F 
9
C  32 to convert 212°F to Celsius.
5
C = 100
EXAMPLE 7
Extra Example 7
Air temperature drops about 3°F for each 1000 ft increase in
altitude. If the air temperature at sea level is 77°F, at what
altitude would you expect the temperature to be 53°F?
Click to see the solution
Checkpoint
The speed of a falling object increases 32 ft/sec for each
second it falls. How many seconds will it take the speed of
a rock dropped from a very high cliff to increase from
50 ft/sec to 210 ft/sec?
t = 5 sec
Example 8
The sum of three numbers is 67. The second number is 4
more than three times the first number. The third number is
three less than two times the first number. Find the three
numbers.
Click to see the solution
QUESTIONS?