Solve Equations with Multiplication and Division

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Transcript Solve Equations with Multiplication and Division

Warm Up
Solve for the variable.
1) m + 10 = 7
2) 18 + j = 54
3) t - 11 = 46
4) x - (-24) = -37
5) The sum of two integers is -42. One integer
is 12. Find the other integer.
2.3 Solving One Step Linear
Equations Using
Multiplication or Division
Standard 5.0: Students solve multistep
problems, including word problems,
involving linear equations and linear
inequalities in one variable and provide
justification for each step.
1) Solve. -5t = 60
To get the variable by itself, which
number needs to be moved?
-5
To move the -5, you have to do the
opposite operation. What operation
will we use?
division
1.
2.
3.
4.
1) Solve -5t = 60
-5 -5
Draw the line to
t = -12
separate the equation
into 2 sides
Divide both sides by -5
Simplify
Check your answer
-5(-12) = 60
1.
2.
3.
4.
2) Solve 24 = 6n
6
6
Draw the line
Divide both sides by 6
4=n
Simplify
Check your answer
24 = 6(4)
3) Solve -3v = -129
1.
2.
3.
4.
v = -126
v = -43
v = 43
v = 126
Answer Now
x
 12
4) Solve
4
You don’t like fractions? Let’s get rid of
them! 
“You can get rid of fractions”
by multiplying both sides of the equation
by the denominator.
1.
2.
3.
4.
x
4) Solve  12
4
Draw the line
x
Clear the fraction –
4 ·  12 · 4
multiply both sides by 4
4
Simplify
Check your answer
x = -48
48
 12
4
2x
5) Solve
= 18
3
1.
2.
Draw the line
Get rid of the fraction –
multiply both sides by
the reciprocal
2x  5  9
 4x  4  20
Try It Out
3x  5  11
10x  4  34
 4x  8  20
2  (5 x)  13
Examples
x
5  3
3
x7
 10
3
y
15

4
a

5
9  6
5
7 g  14  63
5n  6  4
c
t
5 7
 6  12
3
8
r 1
8
3
5m
11 
2
a
 3  2
7
 11  7  3c
d 6
14 
2
17  s
 10
4
Homework:
Finish In class Assignment