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
Kaylis [27]
3 years ago
7

Solve x2 + 9x + 8 = 0 by completing the square. What are the solutions?

Mathematics
1 answer:
solmaris [256]3 years ago
8 0
Answer: (-1,-8)

Explanation:

x^2 + 9x + 8 = 0
x^2 + 9x = -8

Add (9/2)^2 to both sides

x^2 + 9x + (9/2)^2 = -8 + (9/2)^2
(x + 9/2)^2 = -8 + 81/4
(x + 9/2)^2 = -32/4 + 81/4
(x + 9/2)^2 = 49/4

Square root both sides

Sqrt (x + 9/2)^2 = sqrt 49/4
x + 9/2 = plus or minus 7/2

Set x + 9/2 = 7/2:

x + 9/2 = 7/2
x = 7/2 - 9/2
x = -2/2 = -1

Set x + 9/2 = -7/2:
x + 9/2 = -7/2
x = -7/2 - 9/2
x = -16/2 = -8
You might be interested in
What is the answer to y=2•2^x
KATRIN_1 [288]

Answer:

y=4^x

Step-by-step explanation:

7 0
3 years ago
CALCULUS EXPERT WANTED
Vlad [161]

a. Use the mean value theorem. 16 falls between 12 and 20, so

v'(16)\approx\dfrac{v(20)-v(12)}{20-12}=\dfrac{240-200}8=5

(Don't forget your units - 5 m/min^2)

b. v(t) gives the Johanna's velocity at time t. The magnitude of her velocity, or speed, is |v(t)|. Integrating this would tell us the total distance she has traveled whilst jogging.

The Riemann sum approximates the integral as

\displaystyle\int_0^{40}|v(t)|\,\mathrm dt=12\cdot200+8\cdot240+4\cdot220+16\cdot150=7600

If you're not sure how this is derived: we're given 5 sample points, so we can cut the interval [0, 40] into 4 subintervals. The lengths of each subinterval are 12, 8, 4, and 16 (the distances between each sample point), and the height of the rectangle approximating the area under the plot of |v(t)| is determined by the value of v(t) at each sample point, 200, 240, |-220| = 220, and 150.

c. Bob's velocity is given by B(t), so his acceleration is given by B'(t). We have

B'(t)=3t^2-12t

and at t=5 his acceleration is B'(5)=15 m/min^2.

d. Bob's average velocity over [0, 10] is given by the difference quotient,

\dfrac{B(10)-B(0)}{10-0}=\dfrac{700-300}{10}=40 m/min

6 0
3 years ago
A recent survey indicated that 405 out of 500
Sidana [21]

Answer:

The answer is: 81%

Step-by-step explanation:

Divide 405 by 500 and multiply result by 100 to get percent.

405 / 500 = 0.81

0.81 x 100 = 81%

Hope this Helps!! Have an Awesome Day!!

5 0
3 years ago
Read 2 more answers
Use the drop-down menus to answer the questions,
Mashcka [7]

Step-by-step explanation:

survey a specific amount of students and ask then if they spend les that 2 hours a night of studying or 2 or more hours a night studying.

3 0
3 years ago
Read 2 more answers
Is ∞ the same as +∞?
dezoksy [38]

Answer:

infinity and positive infinity are the same

6 0
3 years ago
Read 2 more answers
Other questions:
  • Write the equation of the circle with center (2, 1) and (5, 2) a point on the circle. A) (x − 2)2 + (y − 1)2 = 9 B) (x − 2)2 + (
    14·1 answer
  • What’s the end behavior of g(x)=(5^x-3)+2.5
    7·1 answer
  • What is the circumference of a circle with radius pi?​
    14·1 answer
  • Complete the identity sin(2θ) sin(4θ) cos(2θ) cos(4θ) = ?
    10·1 answer
  • Henry is staining the wooden floor of a court. The court is in the shape of a rectangle. Its length is 54 feet and its width is
    5·1 answer
  • 5 x 2^x= 40 What is the value of x?
    7·1 answer
  • Find g (-6) if g (x)=5 x - 7
    5·1 answer
  • Please help I need this please help please just me help
    6·1 answer
  • Can someone help me please will give brainlist
    9·1 answer
  • Based on the diagram, which is a true statement?
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!