Transcript PowerPoint Presentation - Week 7 Warm-up

Objective 22
Solve one-step equations,
multiply and divide
©2002 by R. Villar
All Rights Reserved
Solve one-step equations, multiply and divide
In the last section we used addition to undo subtraction
and we used subtraction to undo addition.
Addition and subtraction are called inverse operations
of each other.
In this section we will use multiplication and division to
undo each other since they are inverse operations of
each other.
To
multiplication,
The“undo”
opposite
–14’s will
ofcancel
multiplying
leaving
Example: Solve 112 = –14n
we
will
use
division...
byby
n
–14
itself...
is
dividing
by –14.
–14 –14
–8 =
Check the original problem...
n
112 = –14(–8) √
Example:
Solve 3 =
z
9.5
To undo division, we will use multiplication...
3 • 9.5 = z • 9.5
9.5
28.5 =
Check:
z
3 = 28.5
9.5
√
Example:
Solve 2 x  4 1
3
8
To undo multiplication of fractions, we can use the reciprocal.
We will first convert the mixed number into an improper fraction...
3 2
33 3
• x •
2 3
2
8
x = – 99
16
2  99 
33
Check:    
3 16
8
Now,
multiply
both
sides
The reciprocals
Multiply
the right
will
side
cancel
to by
solve
the
reciprocal
of left
2/3...
leaving
for
x...
x on the
side...
√