Transcript Document

Modified Jeopardy 
If you are playing with a
partner, decide how many
points you think the
question is worth
BEFORE you solve.
True or False:
5 less than n =
5- n
False:
n less than 5
5- n
Write an expression
for five less than the
product
of a number n and 8
8n -5
True or False:
n is an algebraic
expression
True!
It has a coefficient (1)
and a variable (n)
Write an algebraic
expression for:
the quotient of the
product of two and n
and m
2n
m
Write a word expression
for this:
(6 ¸ 3)(6 + 3)
Answers vary!
Sample: The quotient of
six and three multiplied by
the sum of six and three
(6 ¸ 3)(6 + 3)
The FIRST step in
evaluating an algebraic
expression is called the
_____________step
The FIRST step in
evaluating an algebraic
expression is called the
substitution step
Evaluate when n = -3:
3n – (-7)
3(-3) – (-7)
(-9) + 7
-2
Evaluate when n = -3
and r = -2:
2
(nr)
2
((-3)(-2))
2
(6)
36
Evaluate when n = -2 :
(n – 3)(n – 4) ÷ (-3n)
(n – 3)(n – 4) ÷ (-3n)
((-2) – 3)((-2) – 4) ÷ (-3(2))
(– 6)(– 6) ÷ (6)
(36) ÷ (6)
6
Evaluate when n = -4
and p = 2:
(3n + 9 -
n
+
2p
np)
n
+
2p
np)
(3n + 9 -4
+
2(2)
(3(-4) + 9 - (-4)(2))
0
(-12 + 9 - (-8))
1
(Trick! Anything to exponent 0 is one )
We solve equations by
using these operations
INVERSE operations
What do you
do to solve
this?
n + (-7) = 8
n + (-7) = 8
+7 +7
n = 15
What do you
do to solve
this?
-4n = -12
-4n = -12
-4
-4
n=3
What do you
do to solve
this?
a – (-9) = -4
a – (-9) = -4
-9 -9
a = -13
Tell 3 things you
could do to both sides
of this equation to
solve it:
-x = 8
Divide both sides by -1
OR
Multiply both sides by -1
OR
Add x then subtract 8 from
both sides
-x = 8
What is the
“wrapping
paper”?
– 3 + 2j = 4
The “wrapping paper” is -3.
In other words, -3 is the FIRST
term that you ‘cancel out’.
– 3 + 2j = 4
Solve
-2b – 3 = -19
-2b – 3 = -19
+3 +3
-2b = -16
-2 -2
b=8
Solve
-8 – 3x= -17
-8 – 3x= -17
+8
+8
-3x = -9
-3 -3
x=3
Solve
1.2k – 6 = 6
1.2k – 6 = 6
+6 +6
1.2k = 12
1.2 1.2
k = 10
Solve (hint:
it’s 3 steps!)
2(-3p + 6) = -18
2(-3p + 6) = -18
2
2
-3p + 6 – 6 = -18 – 6
-3p = -24
-3 -3
p=8
In most word
problems “of”
means what
operation?
In most word
problems “of”
means
MULTIPLICATION
Write an
equation:
4 less than twice
a number n is 6
4 less than twice
a number n is 6
2m – 4 = 6
Two-thirds of a
number n, decreased
by 3, is 12
2n/3 – 3 = 12
The quotient of a
number n and -8,
less 5, is 25
n/(-8) – 5 = 25
Write an equation then
solve:
Jim is 2 years less than
twice his sister’s age.
If Jim is 12 how old is
his sister?
2a – 2 = 12
-2 -2
2a = 12
2
2
a=7