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
Rama09 [41]
3 years ago
7

3.)

Mathematics
1 answer:
kotykmax [81]3 years ago
5 0

Answer:

Let’s find out...

Step-by-step explanation:

21 x 13 = 273

(13 x 20) + (13 x 1) =

260 + 13 = 273

So this one matches

(21 x 10) + 213 =

210 + 213 = 423

Does not match

(30 x 13) - (9 x 13) =

390 - 117 = 273

This one matches

(20 x 10) + (1 x 3) =

200 + 3 = 203

Does not match

You might be interested in
Q # 28 please solve the equation
o-na [289]
The height of the pole = 129.3 ft

sin 36° = height of pole/ hypotenuse
hypotenuse = 220 ft

the height of the pole = 220 sin 36° = 129.3 ≈ 129 ft
4 0
3 years ago
Read 2 more answers
Find the volume of the cylinder.
Amanda [17]
The first one A) :)))))))
3 0
3 years ago
Read 2 more answers
A store is having a sale on chocolate chips and walnuts. For 3 pounds of chocolate chips and 5 pounds of walnuts, the total cost
mrs_skeptik [129]

Answer:

Step-by-step explanation:

3c + 5w = 16

6c + 2w = 22

-6c - 10w = -32

6c  + 2w = 22

-8w = -10

w = 10/8 = 5/4 = $1.25 per lb

3c + 5(1.25) = 16

3c + 6.25 = 16

3c = 9.75

c = $3.25 per lb

5 0
3 years ago
Consider the equation below. (If an answer does not exist, enter DNE.) f(x) = x3 − 6x2 − 15x + 4 (a) Find the interval on which
kozerog [31]

Answer:

a) The function, f(x) is increasing at the intervals (x < -1.45) and (x > 3.45)

Written in interval form

(-∞, -1.45) and (3.45, ∞)

- The function, f(x) is decreasing at the interval (-1.45 < x < 3.45)

(-1.45, 3.45)

b) Local minimum value of f(x) = -78.1, occurring at x = 3.45

Local maximum value of f(x) = 10.1, occurring at x = -1.45

c) Inflection point = (x, y) = (1, -16)

Interval where the function is concave up

= (x > 1), written in interval form, (1, ∞)

Interval where the function is concave down

= (x < 1), written in interval form, (-∞, 1)

Step-by-step explanation:

f(x) = x³ - 6x² - 15x + 4

a) Find the interval on which f is increasing.

A function is said to be increasing in any interval where f'(x) > 0

f(x) = x³ - 6x² - 15x + 4

f'(x) = 3x² - 6x - 15

the function is increasing at the points where

f'(x) = 3x² - 6x - 15 > 0

x² - 2x - 5 > 0

(x - 3.45)(x + 1.45) > 0

we then do the inequality check to see which intervals where f'(x) is greater than 0

Function | x < -1.45 | -1.45 < x < 3.45 | x > 3.45

(x - 3.45) | negative | negative | positive

(x + 1.45) | negative | positive | positive

(x - 3.45)(x + 1.45) | +ve | -ve | +ve

So, the function (x - 3.45)(x + 1.45) is positive (+ve) at the intervals (x < -1.45) and (x > 3.45).

Hence, the function, f(x) is increasing at the intervals (x < -1.45) and (x > 3.45)

Find the interval on which f is decreasing.

At the interval where f(x) is decreasing, f'(x) < 0

from above,

f'(x) = 3x² - 6x - 15

the function is decreasing at the points where

f'(x) = 3x² - 6x - 15 < 0

x² - 2x - 5 < 0

(x - 3.45)(x + 1.45) < 0

With the similar inequality check for where f'(x) is less than 0

Function | x < -1.45 | -1.45 < x < 3.45 | x > 3.45

(x - 3.45) | negative | negative | positive

(x + 1.45) | negative | positive | positive

(x - 3.45)(x + 1.45) | +ve | -ve | +ve

Hence, the function, f(x) is decreasing at the intervals (-1.45 < x < 3.45)

b) Find the local minimum and maximum values of f.

For the local maximum and minimum points,

f'(x) = 0

but f"(x) < 0 for a local maximum

And f"(x) > 0 for a local minimum

From (a) above

f'(x) = 3x² - 6x - 15

f'(x) = 3x² - 6x - 15 = 0

(x - 3.45)(x + 1.45) = 0

x = 3.45 or x = -1.45

To now investigate the points that corresponds to a minimum and a maximum point, we need f"(x)

f"(x) = 6x - 6

At x = -1.45,

f"(x) = (6×-1.45) - 6 = -14.7 < 0

Hence, x = -1.45 corresponds to a maximum point

At x = 3.45

f"(x) = (6×3.45) - 6 = 14.7 > 0

Hence, x = 3.45 corresponds to a minimum point.

So, at minimum point, x = 3.45

f(x) = x³ - 6x² - 15x + 4

f(3.45) = 3.45³ - 6(3.45²) - 15(3.45) + 4

= -78.101375 = -78.1

At maximum point, x = -1.45

f(x) = x³ - 6x² - 15x + 4

f(-1.45) = (-1.45)³ - 6(-1.45)² - 15(-1.45) + 4

= 10.086375 = 10.1

c) Find the inflection point.

The inflection point is the point where the curve changes from concave up to concave down and vice versa.

This occurs at the point f"(x) = 0

f(x) = x³ - 6x² - 15x + 4

f'(x) = 3x² - 6x - 15

f"(x) = 6x - 6

At inflection point, f"(x) = 0

f"(x) = 6x - 6 = 0

6x = 6

x = 1

At this point where x = 1, f(x) will be

f(x) = x³ - 6x² - 15x + 4

f(1) = 1³ - 6(1²) - 15(1) + 4 = -16

Hence, the inflection point is at (x, y) = (1, -16)

- Find the interval on which f is concave up.

The curve is said to be concave up when on a given interval, the graph of the function always lies above its tangent lines on that interval. In other words, if you draw a tangent line at any given point, then the graph seems to curve upwards, away from the line.

At the interval where the curve is concave up, f"(x) > 0

f"(x) = 6x - 6 > 0

6x > 6

x > 1

- Find the interval on which f is concave down.

A curve/function is said to be concave down on an interval if, on that interval, the graph of the function always lies below its tangent lines on that interval. That is the graph seems to curve downwards, away from its tangent line at any given point.

At the interval where the curve is concave down, f"(x) < 0

f"(x) = 6x - 6 < 0

6x < 6

x < 1

Hope this Helps!!!

5 0
3 years ago
Explain the steps you would take to write 36/10 as a decimal
kherson [118]
You just have to make 36/10 into 3 6/10. After that, it would become 3.6
4 0
3 years ago
Read 2 more answers
Other questions:
  • Please help im so stupid
    9·1 answer
  • Don bought his car for $20,350. It is expected to depreciate an average of 11% each year during the first 5 years.
    10·2 answers
  • The deck of a skateboard has and area of 2^5 • 7in^2. what is the area of the skateboard deck
    8·1 answer
  • Express answer in exact form. Show all work for full credit.
    5·1 answer
  • Find the measure of the angle complementary to the given angle.<br> mZy = 15°
    11·1 answer
  • Use the distributive property with factoring to find the equivalent expression.
    6·1 answer
  • Hhhhhhheeeeeeeelp please
    5·2 answers
  • What is the first 5 common multiples of 7 and 20
    6·1 answer
  • The product of the product of 7 and 2 and the product of 8 and p
    10·1 answer
  • If electricity comes from electrons, does morality come from morons?
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!