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
ValentinkaMS [17]
3 years ago
13

I need help please help ​

Mathematics
1 answer:
goldfiish [28.3K]3 years ago
6 0

Answer:

[6, 18]

Step-by-step explanation:

the first matrix has the dimensions 1 x 2 (1 row, 2 columns).  The send has the dimensions 2 x 2.  Because of this it is possible to do matrix multiplication and the result will be a 1 x 2 matrix.

Multiply the column -2,  7 by the row 4, 2:

We get (-2)(4) + (7)(2), which simplfies to 6.  This is the first element of the 1 x 2 product.

Multiply the column 5, -1 by the row 4, 2:  We get (5)(4) + (-1)(2), or 18.

The fourth answer choice is the correct one:  [6, 18]

You might be interested in
The library at a certain university reported that journal prices had increased by 120% over a period of 10 years. The report con
Kipish [7]

Answer:

8% increase

Step-by-step explanation:

In this question, we are asked to calculate the percentage increase that a certain increment will give over a period of 10 years.

Let the increment be x

Mathematically from the question, we can obtain that ;

(1+x)^10 = (1+1.2)

(1+x)^10 = 2.2

1+ x = 2.2^1/10

1+x = 1.082

x = 1.082 - 1

x = 0.082

This means that x = 8.2% which is approximately 8%

6 0
4 years ago
A metallurgist has one alloy containing 21% titanium and another containing 50% titanium. How many pounds of each alloy must he
sweet-ann [11.9K]

x = amount of 21% alloy

y = amount of 50% alloy

The metallurgist wants a combination weighing a total of 44 lb, so

x + y = 44

Each pound of either alloy contributes either 0.21 or 0.5 pound of titanium. The final product needs to be comprised of 37% titanium; weighing at 44 lb, this means it should contain 0.37 * 44 = 16.28 lb. So

0.21x + 0.5y = 16.28

From the first equation,

x + y = 44  ==>  y = 44 - x

Substitute this into the second equation and solve for x:

0.21x + 0.5(44 - x) = 16.28

-0.29x = -5.72  ==>  x = 19.72

Substitute this into the first equation to solve for y:

19.72 + y = 44  ==>  y = 24.28

8 0
3 years ago
The length of a rectangle is 5 centimeters less than twice its width. The perimeter of the rectangle is 80 cm. What are the dime
Sonbull [250]
Hello,

Answer A
Let's the width of the rectangle

2a-5 its length
Teh half perimeter is 80/2=40
a+2a-5=40 ==>3a=45==>a=15 and 2a-5=30-5=25


5 0
3 years ago
Read 2 more answers
The current of a river is 4 miles per hour. A boat travels to a point 30 miles upstream and back in 4 hours. What is the speed o
Maurinko [17]
16 mph is the answer I found after doing the work

7 0
3 years ago
the height of a ball dropped from a 160 foot building after t seconds is represented by h(t)=160-16t^2.how high will the ball be
alekssr [168]

Answer:

The height of the ball after 3 secs of dropping is 16 feet.

Step-by-step explanation:

Given:

height from which the ball is  dropped = 160 foot

Time = t seconds

Function h(t)=160-16t^2.

To Find:

High will the ball be after 3 seconds = ?

Solution:

Here the time ‘t’ is already given to us as 3 secs.

We also have the relationship between the height and time given to us in the question.

So, to find the height at which the ball will be 3 secs after dropping we have to insert 3 secs in palce of ‘t’ as follows:

h(3)=160-16(3)^2

h(3)=160-16 \times 9

h(3)=160-144

h(3)=16

Therefore, the height of the ball after 3 secs of dropping is 16 feet.

8 0
3 years ago
Other questions:
  • What is the answer to 45 − (−28) =
    9·2 answers
  • To qualify for a medical study, an applicant must have systolic blood pressure in the 50% of the middle range. If the systolic b
    5·1 answer
  • Please help me solve this!!
    5·1 answer
  • Please help, i’ll give brainiest answer :)<br> [Image]
    10·1 answer
  • A travel company sells holidays and wants to survey 500 customers stratified by country visited, complete the table.
    5·2 answers
  • (3x + 5y +1) + (5x + y-2)=?​
    12·1 answer
  • Please help with this!! I will mark brainliest! I just need a simple explanation
    12·1 answer
  • 7) Norachai spent $13 on a magazine and some erasers. If the
    5·2 answers
  • Explain the Error: Alan says that two lines in the coordinate plane are perpendicular if and
    15·1 answer
  • A box shaped like a rectangular prism has the dimensions: 4 inches by 2 1/2 inches by 2 inches. The box is filled with smaller c
    14·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!