89. If x, y, and z are numbers such that xy + xz = 100, what is the value of x/5 (3y + 3z) + 10?

A cat chases a mouse. The cat is originally 4 feet behind the mouse, which is running in the same direction along the same route

Verdich [7]

Step-by-step explanation:

The position of the mouse at time t is 4 + 12t.

The position of the cat at time t is 17t.

When the positions are equal:

4 + 12t = 17t

4 = 5t

t = 0.8

It takes 0.8 seconds.

8 0

3 years ago

Insurance companies are interested in knowing the population percent of drivers who always buckle up before riding in a car. Whe

podryga [215]

Answer:

The value is $n = 384$

The correct option is a

Step-by-step explanation:

From the question we are told that

The margin of error is E = 0.05

From the question we are told the confidence level is 95% , hence the level of significance is

$\alpha = (100 - 95 ) \%$

=> $\alpha = 0.05$

Generally from the normal distribution table the critical value of is

$Z_{\frac{\alpha }{2} } = 1.96$

Generally since the sample proportion is not given we will assume it to be

$\^ p = 0.5$

Generally the sample size is mathematically represented as

$n = [\frac{Z_{\frac{\alpha }{2} }}{E} ]^2 * \^ p (1 - \^ p )$

=> $n = [\frac{ 1.96 }{0.05} ]^2 *0.5 (1 - 0.5)$

=> $n = 384$

Generally the margin of error is mathematically represented as

$E = Z_{\frac{\alpha }{2} } * \frac{\sigma }{\sqrt{n} }$

Generally if the level of confidence increases, the critical value of $\frac{\alpha }{2}$ increase and from the equation for margin of error we see the the critical value varies directly with the margin of error , hence the margin of error will increase also

So If the confidence level is increased, then the sample size would need to increase because a higher level of confidence increases the margin of error.

8 0

3 years ago

what equation is solved by the graphed systems of equations? Two linear equations that intersect at the point negative 1, negati

alexgriva [62]

Answer:

1. The equation is solved by the graphed systems of equations is:

Third option: 7x + 3 = x − 3

2. The solution to the system is:

Fourth option: (3,-1)

3. The graph of the system y = −2x + 3 and 2x + 4y = 8 is:

Third option: Line through point (0, 3) and (1, 1). Line through (0, 2) and (4, 0).

4. The solution to the system is:

Second option: Infinite solutions.

5. Bill will have read the same amount of books as Mandy in:

Fourth option: December

Step-by-step explanation:

Question 1. What equation is solved by the graphed systems of equations?

Two linear equations that intersect at the point (-1, -4)=(x,y)→x=-1, y=-4

a. 7x + 3 = x + 3

Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:

7x+3-x=x+3-x

6x+3=3

Subtracting 3 both sides of the equation:

6x+3-3=3-3

6x=0

Dividing both sides of the equation by 6:

6x/6=0/6

Dividing:

x=0 different to the intersection at x=-1, then this is not the equation.

b. 7x − 3 = x − 3

Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:

7x-3-x=x-3-x

6x-3=-3

Adding 3 both sides of the equation:

6x-3+3=-3+3

6x=0

Dividing both sides of the equation by 6:

6x/6=0/6

Dividing:

x=0 different to the intersection at x=-1, then this is not the equation.

c. 7x + 3 = x − 3

Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:

7x+3-x=x-3-x

6x+3=-3

Subtracting 3 both sides of the equation:

6x+3-3=-3-3

6x=-6

Dividing both sides of the equation by 6:

6x/6=-6/6

Dividing:

x=-1 equal to the intersection at x=-1, then this is the equation.

d. 7x − 3 = x + 3

Solving for x: Grouping the x's on the left side of the equation: Subtracting x both sides of the equation:

7x-3-x=x+3-x

6x-3=3

Adding 3 both sides of the equation:

6x-3+3=3+3

6x=6

Dividing both sides of the equation by 6:

6x/6=6/6

Dividing:

x=1 different to the intersection at x=-1, then this is not the equation.

Question 2 (Multiple Choice Worth 2 points) (06.03) Solve the system 2x + 3y = 3 and 3x − 2y = 11 by using graph paper or graphing technology. What is the solution to the system?

The solution to the system is (3, -1) Fourth option

Please, see the attached graph.

Question 3 (Multiple Choice Worth 2 points) (06.03) What is the graph of the system y = −2x + 3 and 2x + 4y = 8?

Third option: Line through point (0, 3) and (1, 1). Line through (0, 2) and (4, 0).

Please, see the attached graph.

Question 4 (Multiple Choice Worth 2 points) (06.03) Solve the system y = 3x + 2 and 3y = 9x + 6 by using graph paper or graphing technology. What is the solution to the system?

Second option: Infinite solutions.

Please, see the attached graph.

Question 5 (Multiple Choice Worth 2 points) (06.03) At the end of April, Mandy told Bill that she has read 16 books this year and reads 2 books each month. Bill wants to catch up to Mandy. He tracks his book reading with a table on his door. Using his table below, what month will Bill have read the same amount of books as Mandy?

Bill

Month Books

May 4

June 8

July 12

August 16

September 20

October 24

November 28

December 32

Books read by Mandy: y=16+2x

Numbers of months since april: x

May: x=1→y=16+2(1)=16+2→y=18 different to 4 (books read by Bill)

June: x=2→y=16+2(2)=16+4→y=20 different to 8 (books read by Bill)

July: x=3→y=16+2(3)=16+6→y=22 different to 12 (books read by Bill)

September: x=5→y=16+2(5)=16+10→y=26 different to 20 (books read by Bill)

October: x=6→y=16+2(6)=16+12→y=28 different to 24 (books read by Bill)

November: x=7→y=16+2(7)=16+14→y=30 different to 28 (books read by Bill)

December: x=8→y=16+2(8)=16+16→y=32 equal to 32 (books read by Bill)

Answer. Fourth option: December

4 0

2 years ago

Machine A and machine B both make car parts.

Klio2033 [76]

504+640=1144 hope this helps!

5 0

2 years ago

7.238/1000 using power of ten rules

Sophie [7]

Answer: 69.38

Step-by-step explanation: Have a brilliant day-Lily ^-^

3 0

3 years ago