what is the answer of
b2 - 81 ?
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Question

Daniel expanded the expression as shown. What errors did he make? Select three options.

[tex]-2(-8x-4y+3/4)=-10x-8y-1 \frac{1}{4}[/tex]

A. The first term should be positive.

B. The second term should be positive.

C. The last term should be -1 1/2, not -1 1/4.

D. He divided -8 by -2 instead of multiplying -8 by -2.

E. He did not simplify the expression completely.

Answer:

Daniel's errors are (a), (b) and (c)

Step-by-step explanation:

To do this, we only need to solve the expression on the left.

So, we have:

[tex]-2(-8x-4y+3/4)=[/tex]

Open bracket

[tex]-2(-8x-4y+3/4)=-2 * -8x -2 * -4y - 2 * 3/4[/tex]

[tex]-2(-8x-4y+3/4)=16x + 8y - \frac{2 * 3}{4}[/tex]

[tex]-2(-8x-4y+3/4)=16x + 8y - \frac{6}{4}[/tex]

[tex]-2(-8x-4y+3/4)=16x + 8y - 1\frac{1}{2}[/tex]

From the expression, we can see that:

So, Daniel's errors are (a), (b) and (c)

Answer:

Its not true because:

Step-by-step explanation:

if you divide by M, with M not being 0, ypu have the equation L=N which is false

Answer:

Step-by-step explanation:

P=2K

50K+75P=1200, using P from above makes this equation become

50K+75(2K)=1200

50K+150K=1200

200K=1200

K=6, since P=2K

P=2(6)=12

So 12 puppies and 6 kittens were adopted.

Answer:

Step-by-step explanation:

56(cos(33) + i sin(33)) = 7(cos(11°) + i sin(11°))

Divide both sides by 7 to get;

8(cos(33) + i sin(33)) = (cos(11°) + i sin(11°))

Expanding and Rearranging gives;

8cos(33) + 8i sin(33)) - cos(11) - isin(11)

This gives ;

8Cos(22) + 8i sin(22) = 8(Cos(22) + I sin(22)

Answer:

x = -5

y = -1

Step-by-step explanation:

Y= -6/5x-7 and y=2/5x+1

then:

-6/5x - 7 = 2/5x + 1

simplify:

-8/5x = 8

divide both sides by 8:

-1/5x = 1

multiply both sides by 5:

-x = 5

x = -5

y = 2/5(-5) + 1 = -2 + 1 = -1

Answer:

x = 13

∠WZX = 57°

Step-by-step explanation:

Because it is a rectangle, ∠XYZ is 90°

∠XZY + ∠YXZ = 90

(5x - 8) + (x + 20) = 90

simplify:

6x + 12 = 90

subtract 12 from each side

6x = 78

divide both sides by 6

x = 13

∠WZX is complimentary to angle (x + 20)

∠WZX = 90 - (13 + 20) = 57°

Answer:

The answer is D

Step-by-step explanation:

We want to see which of the given values is a solution of the inequality:

x < 4

The correct option is A, x = 3.

So the inequality:

x < 4

This means that the variable must be a number smaller than 4.

Then we just need to select the option that is smaller than 4, the only option that meets this requirement is option A, x = 3

Also, as you can see in the number line, the only number that is in the shaded part is x = 3 (from the ones in the options).

If you want to learn more about inequalities, you can read:

https://brainly.com/question/18881247

y = x + 7

For -1:

y = -1 + 7 = 6

y = 7

(x,y) = ( -1, 7)

For 0:

y = 0+ 7

y= 7

(x,y) = (0,7)

For 2:

y = 2+ 7

y= 9

(x,y) = (2,9)

For 4:

y = 4+ 7

y= 11

(x,y) = (4,11)

Tax returns aren't gifts. They're refunds you get because the IRS withdrew too much from your paychecks or had withdrawals from other investment accounts. While it may seem like a great thing to have a tax return come each April, you pay for it the other 11 months of the year.

“A refund means you're giving your cash flow and income to the government in an interest-free loan.” The interest rate on one-year U.S. bonds is around 1.5%, so any interest the government could hypothetically pay on that loan would be very small: about $15 for every $1,000 in your refund.

Answer:

y -10 = -1/9 (x-9)

Step-by-step explanation:

Point slope form is

y-y1 = m (x-x1)

y -10 = -1/9 (x-9)

Answer:

Step-by-step explanation:

Given:

Required equation:

Solve for x:

After 3 days bacteria numbers will reach 400000

Answer:

You add up all numbers then divide it by how many numbers.

Step-by-step explanation:

Example. You have 1, 2, 3, 4, 5.

So 1+2+3+4+5

=15

Then 15÷5

So answer would be 3.

Hope this helps.

Answer:

0.0625 miles

Step-by-step explanation:

There is a faster way but this way makes more sense

1/4 miles = 440 yards

440/4 (since 4 people)

110 yards per person

Put back into miles

Everyone ran 0.0625 miles

Given:

Rate of simple interest = 5%

Time = 4 years

Total interest = $160

To find:

The amount borrowed by Austin from a credit union.

Solution:

The formula for simple interest is:

[tex]I=\dfrac{P\times r\times t}{100}[/tex]

Where, P is principal, r is the rate of interest and t is the number of years.

Putting [tex]I=160,r=5,t=4[/tex] in the above formula, we get

[tex]160=\dfrac{P\times 5\times 4}{100}[/tex]

[tex]160=\dfrac{20P}{100}[/tex]

[tex]160=\dfrac{P}{5}[/tex]

Multiply both sides by 5.

[tex]800=P[/tex]

Therefore, Austin borrowed $800 from a credit union for 4 years.

Answer: that means you have a 3/6 chance which can be simplified to 1/2

1, 3 and 5 are the odd numbers

Step-by-step explanation:

Answer:

the answer is c 1/2

Step-by-step explanation:

since there are 6 numbers on the die that range from 1-6, that means there are three odd numbers, so the probability would be 3/6, which can reduce to 1/2

Answer:

6108795

Step-by-step explanation:

To obtain the number of ways the committee can be selected :

4 teachers from the 12 teachers available and 3 students from the 43 students available

Using combinatorics :

12C4 * 43C3

recall :

nCr = n! ÷ (n - r)!r!

Using calculator :

12C4 = 495

43C3 = 12341

12C4 * 43C3

495 * 12341

= 6108795

Step-by-step explanation:

Convert all into decimals:

0.14, 4/8=0.5,0.33

Answer:

0.14, 0.33, 0.5

      or

0.14, 3/9, 4/8

Answer:

D. -3 for every 1 to the right, in goes down 3.

E. 0, the graph could represent no change over time.

F.

assume the point on the graph is the origin, you can graph these

(2,-4)

(1,-2)

(0,0)

(-1,2)

(-2,4)

(-3,6)

Step-by-step explanation:

Answer:

Using Pythagoras theorem for right angled triangle,

x^2 = 14^2 + 15^2

X= ✓ 196 + 225

X= ✓ 421

X=20.5

Answer:

3

Step-by-step explanation:

Answer:

[tex]\frac{-2}{3}[/tex]

Step-by-step explanation:

y2-y1/x2-x1

-2-2/18-12

-4/6

-2/3

Answer:

choice 4) x = 27, ∠FDG = 62°, ∠GOF = 118°

Step-by-step explanation:

2x + 8 + 4x + 10 = 180°

6x + 18 = 180

6x = 162

x = 27

∠FDG = 2(27) + 8 = 62°

∠GOF = 4(27) + 10 = 118°

Answer:

4

Step-by-step explanation:

I saw karma so i came as fast as I could- welp anyways

Lets test the first equation and coordinate #1 first, 3x-2y=12, and (10,9).

Here we can substitute x as 10 and y as 9, and solve the equation to see if 3(10)-2(9) equals 12 or not.

30-18=12, yep

now lets test the second coordinate, (0, -6). Substitute x as 0 and y as -6, and solve the equation.

3(0)-2(-6)=12

0+12=12, yep

So I definitely works

For II, lets do the same thing

(10, 9) -- 9=3/2*10-6

9=15-6, works

(0, -6) — -6= 3/2*0-6

-6=0-6, also works

So uh therefore I and II both work you see what I mean-

i apologize in advance if i made you more confused than you already are-

Answer:

4

Step-by-step explanation:

The LCD (Least Common Denominator) of all the fractions is 4, so you only need to multiply by 4.

Hope this helps :)

Answer:

Step-by-step explanation:

The greatest denominator is 4 so all the fractions will be eliminated when all terms are multiplied by 4.