8th grade math help?

Question

i pick the best answer

1)rhett rented 2video tapes at the same time and returned them at the same time. if his total bill was $12, how many days late did he return the tapes?
Rental: $3
late fee per day: $0.75
purchased (new): $20
purchased (used): $8

A) 5
B) 4
c) 3
D) 2

2)Allison and jessica each collect stuffed animals. Together they have 30animals. If allison has 3 few than twice what jessica has, how many stuffed animal dopes jessica have?

A) 8
B) 9
C) 11
D 14

3)Which of the following equations is true?
(the little numbers are the exponents)
A) (3X4)₂=3₂X 4₂
B) (3+4)₂=3₂+4₂
C)(3-4)₂=3₂-4₂
D) (3X4)₂=3₂X 4

Answer 1

1st $12
rent is $ 3 for each video is 6 dollars
.75 is late fees .75 *4=$3 x 2=$6


2nd double all the numbers. if u double 11 then its 22 22-3 is 19. 19 +11=30 C

3rd lets just say that the exponet is 2
(3X4) is 12 squared is 144 which is equal to 3 squared
(9) X 4 squared (16) 16X9 is 144 144=144 A

Answer 2

1)rhett rented 2video tapes at the same time and returned them at the same time. if his total bill was $12, how many days late did he return the tapes?
Rental: $3
late fee per day: $0.75
purchased (new): $20 EXTRANEOUS DATA
purchased (used): $8 EXTRANEOUS DATA

2 tapes at (3 + (.75/lateday)Latedays = 12

2(3 + .75L)=12
6 + 1.5L = 12
1.5L = 6
L = 4


2)Allison and jessica each collect stuffed animals. Together they have 30animals. If allison has 3 few than twice what jessica has, how many stuffed animal dopes jessica have?

Allison (a) and Jessica (j) have 30 critters. a + j = 30
Allison has 3 fewer than twice the number Jessica has
a = 2j-3

Substituting the latter 2j - 3 for a in the first equation
a + j = 2j - 3 + j = 3j-3 = 30
multiplying both sides by 1/3 we get
j - 1 =10
Adding 3 to both sides we get
j = 11 (YOUR ANSWER)

Now, a = 2j - 3 so
a = 2(11) - 3 = 22 - 3 = 19

Checking...
Does a + j = 30?
19 + 11 = 30 Yes.


A) 8
B) 9
C) 11
D 14

3)Which of the following equations is true?
(the little numbers are the exponents)
A) (3X4)₂=3₂X 4₂
B) (3+4)₂=3₂+4₂
C)(3-4)₂=3₂-4₂
D) (3X4)₂=3₂X 4

(ab)² = (ab)(ab) = (aa)(bb) = a²b²
That would lead us to believe that A is correct...


But forget algebra for a minute...
3x4=12. 12²=144
3²=9, and 4²=16, and 9x16=144
Does 144 = 144? YES!!!! Again, A appears to be correct

Let's look at the other options
(3+4)²=7²=49
Again, 3²=9, and 4²=16. Does 9+16=49?

(3-4)² = (-1)² = 1.
Again, 3²=9, and 4²=16. Does 9-16=1?

The first solution eliminates the last solution

Answer 3

=================
1. late fee per day = $0.75. rental = $3.
For one tape, x days late, the total bill is:

b = $3.00 + $0.75*x

For two tapes, x days late the total bill is twice that:

b = 2*($3 + $0.75x)

We know the bill is $12:

$12 = 2($3 + $0.75x)
$12 = $6 + $1.50x
$6 = $1.50x
$6/$1.50 = x
4 = x

The tapes were four days late, which is your answer (B).

=================
2. You have two equations (A = Allison's animals, J = Jessica's):

A + J = 30 ("together they have 30")
A = 2J - 3 ("Allison has 3 less than twice Jessica's)

Substitute 2J-3 for A in the first equation:

A + J = 30
(2J - 3) + J = 30
3J = 33
J = 11

Jessica has 11, and Allison therefore has 30-11 = 19. Checking, we verify that 19 is three less than twice 11 (11*2 = 22, 22-3 = 19).

Your answer is (C) 11.

=================
3. Which is true

a. (3*4)^2 = 3^2 * 4^2
(12)^2 = 9*16
144 = 144
This is true.

b. (3+4)^2 = 3^2 + 4^2
7^2 = 9 + 16
49 = 25
This is false.

c. (3-4)^2 = 3^2 - 4^2
(-1)^2 = 9 - 16
1 = -7
This is false.

d. (3*4)^2 = 3^2 * 4
12^2 = 9 * 4
144 = 36
This is false.

The only true one is A.

Answer 4

ok so it costs $3 to rent a movie. Rhett rented 2 videos which would be an initial cost of $6

ok every day that it is late Rhett is charged $.75
there are 2 tapes, so that would be a charge of $1.50 per day.
ok so lets say D=days
$12=1.50*D+6
subtract 6 giving you
6=1.50D
divide by 1.5 giving you
D=6/1.5
D=4
so the answer is B

#2
there are 30 stuff animals
let A= the number Alison has
J= the number jessica has.
A= (2J-3)
30=A+J
30=(2J-3)+J
33=3J
J=11
A=2(11)-3
A=19

so jessica has 11 stuff animals and allison has 19.
The answer would be C)

for 3)
the answer is A
(3+4)= 7²
3²+4²=/=7²
(3-4)²=-1²=1=/=3²-4²
(3*4)²=12²=/=3²*4
3*4=12²=144
3²=9
4²=16
9*16=144
the answer is a

Answer 5

1. total Bill=$12
rental $ 3 for each video= $6
0.75 per day late fee .75 *4=$3 x 2=$6

B 4 days

2. jessica=x
allison = 2x-3
3x-3=30
3x-3+3=30+3
3x=33
x=11 C

3. A
(3x4)^2=12^2=144 3^2x4^2=9 x 16=144

(3+4)^2=7^2=49 3^2+4^2= 9+16=25 no

(3-4)^2=-1^2=1 3^2-4^2=9-16=-7 no

(3x4)^2= 12^2=144 3^2 x4=9x4=36 no

Answer 6

#1. (B) 4
#2. (C) 11
#3. (A) (3*4)^2 = (3^2)*(4^2)

#1
Total bill for 2 video tapes = $12.
So, bill for 1 video tape = $6.
Rent for 1 video tape = $3.
So, fine for 1 video tape = $(6 - 3) = $3.
Fine per day = $0.75
So, no. of days late = $3 / $0.75 = 4.

#2
Let us suppose, Jessica had 'x' animals.
So, Allison had (30 - x) animals.
Twice the no. of animals Jessica had = 2x.
Allison had 3 less than this value = 2x - 3.
But, we have already assumed that Allison had (30 - x) animals.
So, 2x - 3 = 30 - x
or 3x = 33
or x = 11

#3
Revision of some basic formulae.
(ab)^2 = (a^2)*(b^2)
(a + b)^2 = a^2 + 2ab + b^2
(a - b)^2 = a^2 - 2ab + b^2

Here a = 3, b = 4
Put the values in formula and verify.

Answer 7

1 - B - rental = 6 (3 each), i.e. 6 late fees / 1.5 (0.75 each) = 4

2. - B - 9 - x (jessica's animals) + (2x + 3)(these are Allisons) = 30 (total), when we rearrange
3x + 3 = 30
3x = 27
x = 9;

3. A (3x4)x(3x4) = 3x3x4x4 = 3(lower 2)x4(lower 4)

Answer 8

1) bill: 2 dvd rented = $ 6
2 dvd late fee = 2* $ 0.75 * D(days)
total = $ 12

so : 6 + 1.5 D = 12
1.5 D = 6
D = 6/1.5 = 4
so answer is B

2) j : jessica's animals
a: allison's animals

j + a = 30 ----------(1)
a = 2j - 3 -----------(2)

replacing a in (1) by its value found in (2)

j + (2j - 3) = 30
3j = 33
j = 11
so answer is C

3) A is true

Answer 9

Well, I doubt anyone will be willing to do your homework for you- but, I suggest making an equation, and working from there. Use "x" or another variable as your "unknown", and then add the rest of the information you know.

Answer 10

1-b
2-idk
3-idk
but i am sure about number 1