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
Korvikt [17]
3 years ago
5

Mary is half of her sister's age. The sum of their ages is 18. How old is her sister?

Mathematics
1 answer:
Ksivusya [100]3 years ago
8 0

Answer:

Mary's sister is 12 years old.

Step-by-step explanation:

If Mary is half of her sister's age, her sister is 2 times her age.

Represent M as Mary's age...

M+2m=18

3m=18

3m/3=18/3

m=6

But because Mary is a half of her sister's age...

6*2=12

You might be interested in
Use the quadratic function f(x) = 2x2 + 4x +3 to answer the following questions.
GuDViN [60]
The vertex is (-1,1)

Explanation

The vertex formula to find the x coordinate of the formula is -b/2a

So we plug in the values into the formula which is

-4/2(2)

Simplify it

-4/4
=-1
-1 is now the x cord of the vertex.

So now we will plug in the x into the quadratic equation which is 2x^2+4x+3

2(-1)^2 + 4(-1) + 3 = 2 -4 +3

Simplify it

5 - 4= 1

Y=1
So the Coordinates of the vertex is (-1,1)
8 0
3 years ago
The sum of matrices A and B is C.
GuDViN [60]

Answer:

Step-by-step explanation: -3

4 0
3 years ago
What is the value of x in a 30-60-90 triangle with a hypotenuse of x+12 and a longer side of x?
enot [183]
In a 30 - 60 - 90 triangle the side opposite the hypotenuse is 1/2 the hypotenuse and which will be the shorter side. Read this over a couple of times till you realize that (x + 12)/2 is the shortest side.

[(x + 12) / 2]^2 + x^2 = (x + 12)^2 subtract [(x + 12)/2]^2 from both sides.

x^2 = (x +12)^2 - [ (x +12)/2]^2
x^2 = (x + 12)^2  [ 1 - (1/2)^2] You were given this as a question in school? It seems awfully hard.
x^2 = (x + 12)^2 [3/4] 
4x^2 = 3*(x^2 + 24x + 144)
4x^2 = 3x^2 + 72x + 432
x^2 - 72x - 432 = 0 This is a quadratic, do you know what they are?
The solution to this comes to x = 77.56

I don't think I made a mistake, but it is sure possible.Check the numbers and my method. 
4 0
3 years ago
2x-3y> or equal to 12
Drupady [299]

Answer:

it's not greater than it would be 2x-3y because you can add then together because the not the same variable

Step-by-step explanation:

5 0
3 years ago
What is the exact volume of the cylinder?
kenny6666 [7]
V = pi r^2 * h
V = pi * 9 * 6
V = 54 pi in^3
6 0
3 years ago
Read 2 more answers
Other questions:
  • Tangler prism is 12 inches long 7 inches wide and 3 inches tall what is the volume
    5·1 answer
  • What is the minimum value for the function y=2x^2-32x+256
    7·1 answer
  • Factor 7x² – 31x – 20.
    9·2 answers
  • What is (2mn) to the second power Simplified?<br><br><br> Please help!
    6·1 answer
  • What is 13/14 - 1/4 and put it in simplest
    10·2 answers
  • 25 Points Please help
    14·2 answers
  • A: l = h - 7.0<br> B: l= 9/16h<br> C:h = 9/16L<br> D:h = L - 7.0
    11·1 answer
  • What's the answer for 1/2 of 3/5?
    11·1 answer
  • 1 + 1=2 will make brainliest
    7·2 answers
  • Is the point (2,8) a solution of the equation y = 13x + 12?<br> O Yes<br> O No
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!