Multi Variable Equations
Download
Report
Transcript Multi Variable Equations
http://www.mathslideshows.com
Is this a “positive 5” or “plus 5”?
+5 – 2x = 14
positive 5 is the same as a plus 5
BOTH
http://www.mathslideshows.com
HINT: If you don’t see a negative
or positive sign in front of a
number it is always positive.
+5
http://www.mathslideshows.com
Is this a “negative 7x” or “minus 7x”?
2 – 7x = 10
negative 7x is the same as a minus 7x
BOTH
http://www.mathslideshows.com
HINT: The sign in front of the
number BELONGS TO THE NUMBER!
–7
http://www.mathslideshows.com
I will show you 2 ways to solve this equation!
3x 7 5x 13
3x
3x
7 2x 13
13
13
20 2x
2
2
10 x
3x 7 5x 13
5x
5x
2x 7 13
7
7
2x 20
2 2
Same answer!
Which one do you think is easier?
http://www.mathslideshows.com
x 10
WHY?
It is easier if you move
the smaller number of x’s
to one side.
If you move the larger
number of x’s you will end
up with negative x’s
http://www.mathslideshows.com
Solve With x’s on Both Sides
7x 5 3x 23
3x
3x
4x 5 23
5 5
4x 28
4
4
x 7
http://www.mathslideshows.com
Solve With x’s on Both Sides
x 5 6x 20
x
x
5 5x 20
20
20
25 5x
5
5
5 x
http://www.mathslideshows.com
Solve With The Distributive Property
13 = 4(3x – 7) + 5
13 = 12x - 28 + 5
13 = 12x - 23
+23
+23
36 = 12x
__
___
12
12
3 = x
13 = 4(3 3 – 7) +5
13 = 4(9 - 7) + 5
13 = 4(2) + 5
13 = 8 + 5
13 = 13
http://www.mathslideshows.com
Solve With The Distributive Property
3y 6(y 2) 24
3y 6y 12 24
9y 12 24
12 12
9y 36
9 9
y4
http://www.mathslideshows.com
Solve With The Distributive Property
24 6(m 4) 2m
24 6m 24 2m
24 4m 24
24
24
48 4m
4
4
12 m
http://www.mathslideshows.com
Solve With The Distributive Property
8 4(x 3) 32
8 4x 12 32
4x 4 32
4 4
4x 36
4 4
x 9
http://www.mathslideshows.com
Solve With The Distributive Property
4(x 2) 3(x 1)
4x 8 3x 3
3x
-3x
x 8 3
8 +8
x 11
http://www.mathslideshows.com
Solve With The Distributive Property
5(8 x) 3(x 8)
40 5x 3x 24
5x 5x
40 8x 24
24
24
64 8x
8 8
8x
http://www.mathslideshows.com
Solve With The Distributive Property
Challenging 3(4x 20) 4(5 2x)
One!
12x 60 20 8x
8x
8x
20x 60 20
60 60
20x 80
20 20
x4
http://www.mathslideshows.com
The
End!
Take out your study guide!
http://www.mathslideshows.com
#19
1) Get rid of the parenthesis by distributing
2) Combine like terms
3) Move the smaller number of x’s to one side
4) Move all numbers to the other side
5) Get x all by itself
6) Check your answer in the original equation
Circle answer. Show work in the check!
http://www.mathslideshows.com
#20
5(m - 6) = 10
5m - 30 = 10
+ 30 +30
5m = 40
Check
in
the
original
equation!
Get rid of
parenthesis
first by
distributing.
5
5
m=8
5(8 - 6) = 10
5(2) = 10
10 = 10
http://www.mathslideshows.com
Do
PEMDAS
in the
check!
#21
8x - 4 = 3(2x + 8) Get rid of the parenthesis.
8x - 4 = 6x + 24 Get the variables on one side.
-6x
-6x
Subtract 6x from both sides.
2x - 4 = 24
6x
and
–6x
cancel
out
+4 +4
2x
__
= __
28
Add 4 to both sides.
2
2
Divide both sides by 2.
x
= 14
8(14) - 4 = 3(2 14+8) Show your check!
112 - 4 = 3(36)
Finish your check!
108 = 108
http://www.mathslideshows.com
EXTRAS: You can use them the
next day when going over
homework corrections.
copyright©amberpasillas2010
Solve With The Distributive Property
Challenging 2(3x 1) 4(10 2x)
One!
6x 2 40 8x
8x
8x
14x 2 40
2 2
14x 42
14 14
x3
http://www.mathslideshows.com
#
Extra
13 = 4(3x – 5) + 9
13 = 12x - 20 + 9
13 = 12x - 11
+11
+11
24 = ___
12x
__
12
12
Show work in the check!
13 = 4(3 • 2 – 5) +9
13 = 4(6 - 5) + 9
13 = 4(1) + 9
13 = 4 + 9
13 = 13
2 = x
http://www.mathslideshows.com
If you have trouble viewing you
need MathType software:
To see all math formulas
correctly you need to install
MathType software, similar to
equation editor and is
available for free at Design
Science website .
http://www.mathslideshows.com
For more information on
Math Slideshows visit:
http://www.mathslideshows.com/
http://www.mathslideshows.com