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
crimeas [40]
4 years ago
13

How do I do this one ?

Mathematics
1 answer:
My name is Ann [436]4 years ago
6 0
Answer: fourth option -x² + 18x - 74

Explnation:

Since all the equations are parabolas, to find which one has a maximum at (9,7) you must verify two conditons:

1) the parabola opens downwards, and

2) the vertex is (9,7)

The first condtion means that the coefficient of the quadratic term is negative.

All the equations given meet that condition.

Therefore you have to find the vertex.

The vertex of a parabola is at the point where x = - b /(2a)

So, prove one by one.

Equation               b         a         x = -b/(2a)   

-x² -18x - 88        -18      -1         - 9 ⇒ not our equation (we aim to x = 9)

(jump to the last option)

-x² + 18x - 74        18      -1          9 ⇒ y = - (9)² + 18(9) - 74 = -81+162-74=7

Therefore, the last equation is the one.

You might be interested in
Christine's age is two times sydney's age. the sum of their ages is 54. what is sydneys age?
Naddika [18.5K]
Let Sydney's age be x
Christine's age is 2x

Sum of their age is 54
x + 2x = 54
3x = 54
x = 18

Sydney is 18 years old.
6 0
3 years ago
pencils are sold in packages of 5. explain why we need 6 packages in order to have enough for 27 students
Natasha_Volkova [10]
Because 5x6 is 30 that is plenty for 27 kids but 5x5 is only 25, that is not enough for 27 kids. 
6 0
4 years ago
Read 2 more answers
Mackenzie has $70 in a savings account. The interest rate is 5%, compounded annually.
sladkih [1.3K]

Answer:

She will have $73.5 in 1 year

Step-by-step explanation:

She has $70 and the interest rate is 5% so we need to add 5% to the initial value

x = $70 + $70 * 5%

5% = 5/100

x = $70 + $70 * 5/100

x = $70 + $3.5

x = $73.5

She will have $73.5 in 1 year

8 0
3 years ago
2+d=2-3(d-5)-2 Pls show work
defon
2 + d = 2 - 3(d- 5) - 2

First, cancel 2 on both sides. / Your problem should look like: d = -3(d - 5) - 2
Second, expand. / Your problem should look like: d = -3d + 15 - 2
Third, simplify -3d + 15 - 2 to get -3d + 13. / Your problem should look like: d = -3d + 13
Fourth, add 3d to both sides. / Your problem should look like: d + 3d = 13
Fifth, add d + 3d to get 4d. / Your problem should look like: 4d = 13
Sixth, divide both sides by 4. / Your problem should look like: d =  \frac{13}{4}

Answer as fraction: d =  \frac{13}{4}
Answer as decimal: d = 3.25

3 0
4 years ago
Read 2 more answers
What is the unit rate of 450 miles in 7 hours?
erica [24]

Answer:60 mph

Step-by-step explanation:

8 0
3 years ago
Read 2 more answers
Other questions:
  • Find the product of 8341 and 235
    15·1 answer
  • PLEASE HELP!! I think the answer is 62 but im not completely sure.
    12·2 answers
  • What is 8x2 + 48x factored
    10·2 answers
  • What is meant by the term total installment price?
    12·1 answer
  • Express 0.7723 as a fraction.​
    5·2 answers
  • the population of a particular city is given by the function p(t) = 72,300(1.03)t, where t is time in years and p(t) is the popu
    7·1 answer
  • A and B together complete a work in 20days. They worked together for 5days and B leaves. How long will A takes to finish the rem
    11·1 answer
  • The symbol used to seperate the tenths and ones is called a?
    5·2 answers
  • A rocket is launched from a tower. The height of the rocket, y in feet, is related to the time after launch, x in seconds, by th
    12·2 answers
  • Dan deposited $700 in a savings account. At the end of 3 year, he had earned $115.50 in simple interest. What interest rate did
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!