1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
FromTheMoon [43]
4 years ago
9

What is the factored form of the expression? t2 – 81

Mathematics
1 answer:
blondinia [14]4 years ago
6 0
We have that
t²<span> – 81
</span>
we know that
A difference of two perfect squares, <span> (A</span>²<span> - B</span>²)<span>  </span><span>can be factored into </span><span> (A+B) • (A-B)
</span> let
A²-------> t²
B²-------> 9²
then
(t² – 9²)------->(t+9)*(t-9)

the answer is
(t+9)*(t-9)


You might be interested in
A child lets go of a balloon that rises at a constant rate. 5 seconds after it was released, the balloon is at a height of 16 fe
Mama L [17]

Answer:

1. h = 2.4t + 4

2. 4 feet

3. 220 feet

Step-by-step explanation:

1. Write a linear model for the height, h, of the balloon as a function of the number of seconds, s that it has been raising.

Since the balloon rises at a constant rate, we find this rate by using the initial and final values of height and time at 5 seconds and 20 seconds respectively which are 12 feet and 52 feet respectively.

So, rate = gradient of line

= change in height/change  in time

= (52 ft - 16 ft)/(20 s - 5 s)

= 36 ft/15 s

= 2.4 ft/s

Now the equation of the line which shows the height is gotten from

(h - h')/(t - t') = rate

Using h'= 16 feet and t' = 5 s, we have

(h - 16)/(t - 5) = 2.4

h - 16 = 2.4(t - 5)

h - 16 = 2.4t - 12

h = 2.4t - 12 + 16

h = 2.4t + 4

where h is the height of the balloon above the ground and t is the time spent in the air in seconds.

2. What was the height of the balloon initially before the child let it go?

We obtain the initial height of the balloon before the child let go at time, t = 0 the time before the child let go.

So, substituting t = 0 into the equation for h, we have

h = 2.4t + 4

h = 2.4(0) + 4

h = 0 + 4

h = 4 feet

So, the height of the balloon before the child let go is 4 feet above the ground.

3. Use your model to predict the height of the balloon after 90 seconds.

We insert t = 90 s into the equation for h. So,

h = 2.4t + 4

h = 2.4(90) + 4

h = 216 + 4

h = 220 feet

So, the height of the balloon after 90 s is 220 feet above the ground.

8 0
3 years ago
Solve the following system by elimination:<br> 4x+3y=2<br> 5x + 4y = 3
MAXImum [283]

Answer:

5x+4y=3

- 4x+3y=2

-----------------

x+y=1

5 0
3 years ago
You received a $178 per month raise. That was a 5% increase. What was your monthly salary before the increase? Show work please
zzz [600]

Answer: 169.52

Step-by-step explanation

%increase which is 5% =100 x final - initial

                                                   ---------------------

                                                         initial

the initial is $169.52

and the final  $178

3 0
3 years ago
What is the median of the data set?
Artist 52 [7]

Answer:

11.7

Step-by-step explanation:

4 0
3 years ago
Read 2 more answers
A car company is going to issue new ID codes to its employees. Each code will have one digit followed by four letters. The lette
scoray [572]

2734375 employee ID codes can be generated

<em><u>Solution:</u></em>

Given that Each code will have one digit followed by four letters

The letter V and the digits 3, 4, and 5 will not be used

So, there are 25 letters and 7 digits that will be used

Assume that the letters can be repeated

Each code = 1 digit + four letters

digits 3 , 4 , 5 cannot be used

Therefore, the remaining digits are 1, 2, 6, 7, 8 , 9, 0

7 digits that will be used

One digit can be chosen from 7 digits in 7 ways

The first letter can be chosen from 25 letters in 25 ways

Since given that letters can be repeated

The second letter can be chosen from 25 letters in 25 ways

Similarly, the third letter can be chosen from 25 letters in 25 ways

Similarly, the fourth letter can be chosen from 25 letters in 25 ways

<u><em>Therefore, the total number of ways are:</em></u>

\rightarrow 7 \times 25 \times 25 \times 25 \times 25 = 7 \times 25^4\\\\ \rightarrow 2734375

Thus 2734375 employee ID codes can be generated

3 0
3 years ago
Other questions:
  • If someone dives 300 feet in 2 minutes and another person dives 6750 ft in 45 minutes let X represent the time of dive and y rep
    13·1 answer
  • Which value of m makes this statement true?
    10·2 answers
  • Simplify<br> 7(x+3)<br> I am in 7th grade
    9·2 answers
  • Evaluate √81/√9<br> help lolll
    5·2 answers
  • Sara graphs a line passing through points that represent a proportional relationship. Which set of points could be on the line t
    15·2 answers
  • What is the answer to this problem?
    6·1 answer
  • How many times does 5 go in to 47
    6·1 answer
  • A student completes about 8 problems every 3 minutes. At this rate, how long will it take the student to complete 20 problems?
    11·1 answer
  • A figure is going to be dilated by a scale factor of 3.5.
    13·1 answer
  • HELP!!!
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!