S
ECTION
6.1
S
OLVING
E
QUATIONS
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R
EVIEW
: S
IMPLIFYING
E
XPRESSIONS
When simplifying an expression, we use BEDMAS to
decide which operation to goes first
B
rackets,
E
xponents,
D
ivide,
M
ultiply,
A
dd,
S
ubtract
Ex: Simplify the following expressions:
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I) S
OLVING
BY
G
OING
B
ACKWARDS
:
“Solving an equation” means finding a value for “x”
(variable) so that both sides of an equation will be equal
When we solve for a variable (x), we perform the operation
in the reverse order of BEDMAS
SAMDEB...
Suppose we know that “x” is equal
to 5. What values goes in the box?
1. Multiply
“x” by 3
2. ADD
8 to 15
3. Answer
is 23
In contrast, when asked to solve for “x”,
the answer on the right is given, but not
the value of “x”.
1. Answer
is 23
2. Subtract
8 from 23
3. Divide
15 by 3
Reverse the operation to solve for “x”
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E
XAMPLE
: S
UPPOSE
YOU
KNOW
THE
VALUE
OF
“
X
”,
LIST
THE
STEPS
TO
GET
THE
ANSWER
1. Multiply
“x” by 3.6
2. Subtract
10 from
the value
3. What you end
up with will be
your Answer
b) Suppose the answer was 31.4, what is the value of “x”?
1. Answer
is 31.4
2. Add 10
to 31.4
3. Divide your
value by 3.6
“x” is equal to 11.5. Check your answer
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E
X
: W
HEN
A
NUMBER
IS
DIVIDED
BY
5
AND
THEN
SUBTRACTED
BY
3,
THE
RESULT
IS
8. W
HAT
IS
THIS
NUMBER
? W
RITE
AN
EQUATION
To solve for this number,
do the opposite operation
1. Answer
is 8
2. Add 3
to 8
3. Multiply your
value by 5
“x” is equal to 55. Check your answer
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P
RACTICE
: A
NUMBER
IS
DIVIDED
BY
4,
MULTIPLIED
BY
3,
AND
THEN
ADDED
5
TO
EQUAL
29. W
HAT
IS
THE
NUMBER
?
To solve for this number,
do the opposite operation
1. Answer
is 29
2. Subtract
5 from 29
3. Multiply your
value by 4
4. Divide your
value by 3
“x” is equal to 32. Check your answer
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H
OMEWORK
:
P 272 # 6, 8 10, 11, 16, 18, 21, 24
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