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
vichka [17]
3 years ago
9

Solve for r whats the answer

Mathematics
2 answers:
NARA [144]3 years ago
7 0
(9r-18)/2 < 45
9r-18< 90
9r< 108
r < 12
tankabanditka [31]3 years ago
5 0
R=12 because in order to get rid of the 2 in the denominator you have to multiply both sides by 2. Then the equation reads 9r-18<90. Next add the 18 to her 9r<108. And lastly divide by 9 to solve for r. Which in this case is 12
You might be interested in
Explain how you would use fractions bars to find the quotient of 10/12 ÷ 4/6.what is the quotient?
____ [38]

Answer:

5/4

Step-by-step explanation:

10/12×6/4

60÷48=1.25 or 5/4

5 0
2 years ago
What is the solution to the system of equations represented by the two equations?
nexus9112 [7]
Just substitute the first equation into the second and solve for x: <span><span>32</span>x=−<span>12</span>x+4⟹2x=4⟹x=2</span><span>Now, since y = 3/2 * x, we have y = 3 and we are done.</span>
8 0
3 years ago
Give two systems of equations that would be easier to solve by substitution than by elimination. Then give two systems that woul
Daniel [21]
These techniques for elimination are preferred for 3rd order systems and higher. They use "Row-Reduction" techniques/pivoting and many subtle math tricks to reduce a matrix to either a solvable form or perhaps provide an inverse of a matrix (A-1)of linear equation AX=b. Solving systems of linear equations (n>2) by elimination is a topic unto itself and is the preferred method. As the system of equations increases, the "condition" of a matrix becomes extremely important. Some of this may sound completely alien to you. Don't worry about these topics until Linear Algebra when systems of linear equations (Rank 'n') become larger than 2.
5 0
2 years ago
The water works commission needs to know the mean household usage of water by the residents of a small town in gallons per day.
valina [46]

Answer:

A sample of 179 is needed.

Step-by-step explanation:

We have that to find our \alpha level, that is the subtraction of 1 by the confidence interval divided by 2. So:

\alpha = \frac{1 - 0.85}{2} = 0.075

Now, we have to find z in the Ztable as such z has a pvalue of 1 - \alpha.

That is z with a pvalue of 1 - 0.075 = 0.925, so Z = 1.44.

Now, find the margin of error M as such

M = z\frac{\sigma}{\sqrt{n}}

In which \sigma is the standard deviation of the population and n is the size of the sample.

A previous study found that for an average family the variance is 1.69 gallon?

This means that \sigma = \sqrt{1.69} = 1.3

If they are using a 85% level of confidence, how large of a sample is required to estimate the mean usage of water?

A sample of n is needed, and n is found for M = 0.14. So

M = z\frac{\sigma}{\sqrt{n}}

0.14 = 1.44\frac{1.3}{\sqrt{n}}

0.14\sqrt{n} = 1.44*1.3

\sqrt{n} = \frac{1.44*1.3}{0.14}

(\sqrt{n})^2 = (\frac{1.44*1.3}{0.14})^2

n = 178.8

Rounding up

A sample of 179 is needed.

7 0
3 years ago
The sum of two numbers is 31.5. The difference is 5.25. Find the numbers
SVEN [57.7K]
The numbers can be 5.25 and 26.25
6 0
3 years ago
Other questions:
  • Can someone tell me if the following steps in the correct order or where I went wrong? In experimental studies, we follow a logi
    14·2 answers
  • Please help please !!!!!!! IF YOU KNOW THE ANSWER PLZ TYPE IT
    5·1 answer
  • A farm uses a circular system to water the crops. The arm on the system (the radius) is 400 meters long. What area of land can i
    14·1 answer
  • A bicycle store cost 2400 per month to opérate. The store pays an average of 60 per bike. The average selling price of each bicy
    5·1 answer
  • A president, treasurer, and secretary, all different, are to be chosen from a club consisting of 10 people. How many different c
    14·1 answer
  • Which equation can be solved to find one of the missing side lengths in the triangle?
    11·1 answer
  • The circumference of a circle is 18 m. Find its diameter, in meters.<br> quick answers please
    10·1 answer
  • Which set of numbers is NOT in the solution set of the inequality x &lt; 12?
    13·1 answer
  • Ian wanted to display some photos of his recent vacation to Surf City Beach. He used seashells he collected at the beach to deco
    15·1 answer
  • The perimeter of tinas rectangular garden is 60 feet
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!