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
insens350 [35]
3 years ago
8

A school library spends $80 a month on magazines. The average price for magazines bought in January was 70 cents more than the a

verage price in December. Because of the price increase, the school library was forced to subscribe to 7 fewer magazines. How many magazines did the school library subscribe to in December?
Mathematics
1 answer:
gregori [183]3 years ago
4 0

Answer:

  32 magazines

Step-by-step explanation:

If x is the number of subscriptions in December, then the number in January is x-7.

The relationship between the average price of magazines in the two months is ...

  80/(x-7) -80/(x) = 0.70 . . . . . . . . .Jan price - Dec price = 0.70

  80(x) -80(x -7) = 0.70(x)(x-7) . . . . multiply by the denominators

  0.7x^2 -4.9x +560 = 0 . . . . . . . . put in standard form

  x^2 -7x +800 = 0 . . . . . . . . . . . . . divide by 0.7

  (x -32)(x +25) = 0 . . . . . . . . . . . . . factor

The product is zero when one of the factors is zero. x=32 or -25. The sensible solution for this problem is x=32.

The school library subscribed to 32 magazines in December.

You might be interested in
I chose circle is closed and graph is shaded to the left of the circle and it said that was wrong. Please help, thank you
Tems11 [23]
The circle is closed and the graph is shaded to the right also there’s a negative on the x, you have to get rid of it first by dividing by -1 and then you switch direction of the less than or equal to greater than or equal because you divided by negative

6 0
3 years ago
7. Use the quotient rule to simplify the following expression. Assume that x>0.
NeTakaya
Quotient rule says we can divide 192 and 3 because they are both under the radical. This gives us the square root of 64.

We can also divide x^3 and x to get x^2.

The square root of 64x^2 is 8x
8 0
3 years ago
Use the function f(x) = 2x3 - 3x2 + 7 to complete the exercises.
leonid [27]

Answer:

Step-by-step explanation:

The value of the function f(x) at x=a can be determined by substituting a instead of x into the function expression.

1. When x=-1, then

f(-1)=2\cdot (-1)^3-3\cdot (-1)^2+7=-2-3+7=2.

2. When x=1, then

f(1)=2\cdot 1^3-3\cdot 1^2+7=2-3+7=6.

3. When x=2, then

f(-1)=2\cdot 2^3-3\cdot 2^2+7=16-12+7=11.

4 0
2 years ago
Read 2 more answers
Which is an example of a linear equation?
kobusy [5.1K]

Answer:

Step-by-step explanation:

A. (x, y)  is not an equation.

B. 2 + 7 = 9  Not a linear equation, as there is no variable.

C. 3x + 5 = 20  This is a linear equation.

D. y = 2x + 1  This is a linear equation.

5 0
3 years ago
How does supply and demand affect consumers?
Aleks [24]
The answer would be choice A.
7 0
3 years ago
Read 2 more answers
Other questions:
  • Which is the best estimate for the mass of a bicycle?
    14·1 answer
  • Evaluate 8+6÷2+(2+10) help and work with answer please
    8·2 answers
  • The center on the basketball team scored 19 of the team’s 98 points. What percent of the points did he score?
    14·2 answers
  • If the airplane had to return to the airport, how far would it have to travel?
    7·2 answers
  • Please give me the correct answer.​
    7·1 answer
  • Please help me, ASAP tyyy
    5·1 answer
  • The difference of two numbers is 3. Their sum is 25.find the numbers
    14·2 answers
  • Find the measurement of segment WY. Assume that each figure is not drawn to scale. Express your answer as a decimal and do NOT i
    10·2 answers
  • Answer ?? It’s multiplicity
    14·1 answer
  • Last Wednesday, students could choose ham or turkey sandwiches for lunch. The cafeteria made 100 sandwiches in all, 85% of which
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!