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
ira [324]
4 years ago
12

Find the missing number ___:7 = 12:21a.14b.12c.4d.3

Mathematics
1 answer:
Novay_Z [31]4 years ago
6 0
x:7=12:21\to\dfrac{x}{7}=\dfrac{12}{21}\ \ \ |cross\ multiply\\\\21x=7\cdot12\\21x=84\ \ \ |divide\ both\ sides\ by\ 21\\\boxed{x=4}\\\\Other\ method:\\\dfrac{x}{7}=\dfrac{12}{21}\\\\21:7=\boxed3\to12:\boxed3=4\\\\\boxed{\frac{4}{7}=\frac{12}{21}\to4:7=12:21}
You might be interested in
A bag contains 3 red,4 green, and 5 blue marbles. Three marbles are drawn at random. What is the probability that all three are
Reptile [31]

Answer:

1/22

Step-by-step explanation:

assuming that the marbles drawn are not replaced:

P(red) = 3/12 or 1/4

P(green) = 4/11

P(blue) = 5/10 or 1/2

multiply the probabilities together:

1/4 x 4/11 x 1/2 = 1/22

8 0
2 years ago
Complete the square to re-write the quadratic function in vertex form:<br> y = x2+ 10x - 2
Blababa [14]

Answer:

<h3>             \bold{y=(x+5)^2-27}</h3>

Step-by-step explanation:

                                      y = x^2+ 10x - 2\\\\y = x^2+ 2\cdot x\cdot5+5^2-5^2 - 2\\\\y=(x+5)^2-25-2\\\\y=(x+5)^2-27

8 0
4 years ago
A can of soda weighs 336 grams. Find the weight in kilograms of 15 cans.
zaharov [31]

Answer:

5.04

Step-by-step explanation:

1 can equals to 336 grams

so 15 cans will equal to 336 X 15

which is 5040grams

now covert it into kg by dividing it by 1000

which 5.04

4 0
3 years ago
Sarah is collecting recyclables for a science project. on the first day she collects 35 recyclable objects. on the second day sh
Svet_ta [14]
The scneario here expressed is an aritmetic sequence because it can be explained like this: 

<span><span><span>a1</span>=35
</span><span><span>an</span>=<span>a<span>n−1</span></span>+<span>17

So all the variables can fit in and will be better explained than a geometric sequence in which you need a common ratio and that is not needed in this case</span></span></span>
4 0
3 years ago
Read 2 more answers
Determine the reveune for selling 500 helmets
Tasya [4]

Answer:

x is the price the helmets were sold at.

y is the business expenses.

r is the revenue.

500x - y = r

Step-by-step explanation:

500x - y = r

We multiply x, the price that the helmets were sold at. Then we subtract y, which is the business expenses. After this, we get r, our revenue.

4 0
3 years ago
Other questions:
  • △ XYZ∼ △ DEF, YZ is 10 meters, ​ XZ ​ is 15 meters, and EF is 8 meters. What is ​ DF?
    11·2 answers
  • A rug covers 79 square feet of the floor. What is the approximate length of one side of the rug
    14·1 answer
  • A trail runner gets a new map of her favorite mountain.
    10·1 answer
  • How do you find the gcf of 2 numbers
    9·2 answers
  • What is the value of sin 0 given that (-3,7) is a point on the terminal side 0
    15·1 answer
  • Find the value of x+10=11
    5·1 answer
  • Sandy needs to make 6 bows to put on her presents. She plans to use 18 inches of ribbon for each bow. How much ribbon does Sandy
    6·1 answer
  • F(x) = x^2<br> g(x) = –2x^2<br> Which option could show the graphs of f and g?
    14·1 answer
  • U should totally help me out fellow hawt person
    10·2 answers
  • 17. If a triangle has sides of 21 and 36, what is the range for the shortest side?
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!