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
VMariaS [17]
3 years ago
9

Given a = 2i+j – 2k b= -1 – 7j+k Find a x b

Mathematics
1 answer:
castortr0y [4]3 years ago
7 0

Step-by-step explanation:

a = 2i + j - k

b = -1 -7j + k

a × b = (2i + j - k) (-1 + 7j + k)

-2i + 14ij + 2ik - j + 7j^2 + jk + k -7jk - k^2

-2i + 14ij + 2ik -j +7j^2 +jk - 7jk + k - k^2

-2i + 14ij + 2ik - j +7j^2 - 6jk + k - k^2

You might be interested in
A baseball team had 75 players show up for tryouts last year and this year had 90 players show up for tryouts. Find the percent
BigorU [14]

Answer:

20%

Step-by-step explanation:

Subtract the original number from the new number: 90-75=15

The increase is 15

Now divide the increase by the original number: 15/75=.20

Then multiply your answer by 100: .20x100=20

5 0
3 years ago
No one is answering i posted this question 2 times, this is my 3rd time please answer.
Dahasolnce [82]

Answer:

13

Step-by-step explanation:

First, fill in 3 boxes of the table using the given information (blue numbers on the attached table)

"Of the 32 students that have a cell phone, 19 students do not have a tablet."

The top row of the table is students who have a cell phone.  Therefore, place 19 in the box in this row that is in the "no tablet" column.

"Of the 70 students that have a tablet, 57 students do not have a cell phone."

The first column of the table is students who have a tablet.  Therefore, place 57 in the box in the 2nd row of this column.

"11 students do not have a cell phone or a tablet."

Find the "no cell phone" row and the "no tablet" column and place 11 in the box that coincides.

We can calculate the blank totals using addition (shown by green numbers on the attached table)

  • Total students with no cell phone = 57 + 11 = 68
  • Total students with no tablet = 19 + 11 = 30

To calculate the number of students who have a cell phone AND a tablet:

⇒ Total students with a cell phone <em>minus</em> students with a cell phone but no tablet

⇒ 32 - 19 = 13

4 0
2 years ago
Suppose a family drives at an average rate of 60 mi/h on their way to visit relatives and then an average rate of 40 mi/h on the
hammer [34]

Answer:

Part A) 2 hours

Part B) d/60 hours

Part C) 48 miles/hour

Step-by-step explanation:

Part A) Let "d" be the distance in miles the family traveled to visit their relatives. How many hours did it take to drive there?

we know that

Let

x ----> the time it take on their way to visit relatives in hours

y ---> the time it take on the way back in hours

we know that

The distance of the way to visit is equal to the distance of the way back

The speed multiplied by the time is equal to the distance

so

60x=40y -----> equation A

y=x+1 -----> equation B

substitute equation B in equation A and solve for x

60x=40(x+1)

60x=40x+40

20x=40

x=2 hours

Find the value of y

y=2+1=3 hours

d=60x

The time it take on their way to visit relatives is 2 hours

The time it take on the way back is 3 hours

Part B) In terms of "d," how many hours did it take to drive there?

we have that

The distance is equal to the speed multiplied by the time

d=60x

Solve for x

x=d/60 hours

Part C) Write and solve an equation to determine the distance the family drove to see their relatives. What was the average rate for the entire trip?

To find the average rate for the whole trip we will need the total distance and the total time

The distance of the way to visit is

d=60x

substitute the value of x

d=60(2)=120 miles

so

The total distance is

120(2)=240 miles

we know that the total time is

2 + 3 =5 hours

The average rate for the complete trip is

240/5=48 miles/hour

5 0
3 years ago
Read 2 more answers
Instructions: Find the missing side of the triangle.<br> 24 and 7
ANTONII [103]
We can use the Pythagorean theorem to solve this. The Pythagorean theorem is a^2 + b^2 = c^2. We already have a and b, we need to find c. 24^2 + 7^2 is 625. Then, we need to find the square root of 625 to find c. The answer is 25. x = 25.
5 0
3 years ago
Add. 7 2 15+5 2 3+9 13 15 plz help btw its a fraction
LUCKY_DIMON [66]
How could it be a fraction? All the numbers are whole & no division? May I assume the #s listed next to each other are multiplied, i.e. 7 2? If so,...

multiply first...
14 * 15 + 10*3 + 1755 (9*13*15)
210 + 30 + 1755
1,995
8 0
3 years ago
Other questions:
  • Identify the prime factorization for the given number. 6 A. 2 × 2 × 3 B. 2 × 3 C. 1 × 6 D. 1 × 2 × 3 × 6
    5·1 answer
  • Phyllis paid $408 for new wall-to-wall carpeting in her living room. The carpeting was $12 per square yard, plus a $120 installa
    5·1 answer
  • When x = 5, the value of the expression –2(x – 10) is
    14·2 answers
  • Which set is a function?
    15·1 answer
  • Has a center at (2,-1) and contains the point (4,5)
    12·1 answer
  • PLEASE HELP WILL GIVE BRAINLIEST TO CORRECT ANSWER!!
    11·1 answer
  • Evaluate W - X if w = 18 and x = 6.<br> Giving BRIANLIEST
    12·1 answer
  • Can I get help on this math question I will mark brainliest if correct plus 15 points.
    11·2 answers
  • Plz help me with this!!!!!!!!
    5·1 answer
  • <img src="https://tex.z-dn.net/?f=7%20%5Cfrac%7B2%7D%7B3%7D%20%20" id="TexFormula1" title="7 \frac{2}{3} " alt="7 \frac{2}{3}
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!