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
Alinara [238K]
3 years ago
10

Solve by completing the square: x^2 + 3x - 9 = 0

Mathematics
2 answers:
tekilochka [14]3 years ago
6 0

Answer:

Step-by-step explanation:

x^2 + 3x - 9 =0

By comparing with the equation ax^2+bx+c = 0,

we get,

a = 1, b=3, c = -9

we know the formula for x is,

x = (-b±√(b^2 - 4ac))/2a

x = (-3±√45)/2

x = (-3±3√5)/2

x = (-3+3√5)/2, (-3-3√5)/2

My name is Ann [436]3 years ago
3 0

Answer:

2 solutions. x = -3/2 + 3/2 * sqrt(5) and x = -3/2 + -3/2 * sqrt(5)

Step-by-step explanation:

<h3>Let's solve your equation step by step.</h3>

x^2 + 3x −9 = 0

For this equation: a=1, b=3, c=-9

1x^2 + 3x+ −9 = 0

Step 1: Use quadratic formula with a=1, b=3, c=-9.

x = (-b ± \sqrt{b^2 - 4ac})/2a

x = (-3 ± \sqrt{3^2 - 4(1)(-9)})/2a

x = (-3 ± \sqrt{45})/2

x = -3/2 + 3/2 * sqrt(5) or x = -3/2 + -3/2 * sqrt(5)

You might be interested in
The Hawks are starting a babysitting business. They charge an initial deposit of $25 and a rate of $4 an hour. A linear model is
Sauron [17]
What’s the question so I can answer it.
7 0
3 years ago
Hellppp plz will mark brainliestttt
AlekseyPX

Answer:

not a function i think

Step-by-step explanation:

have a nice day hope this helps

3 0
3 years ago
The value of n in the inequality 3n + 1 &lt; 7 is
aliya0001 [1]

3n + 1 < 7

Solve:

3n < 6

n < 2

The answer is C.

8 0
3 years ago
A ball is thrown upward from the top of a 40 foot high building at a speed of 80 feet per second. The ball's height above
tekilochka [14]

it takes 5 seconds to reach a height of 40 ft. and It takes 2.5 seconds to reach maximum height.

Let h(t) represent the height of the ball at time t.

Given that the height is given by:

h(t) = -16t² + 80t + 40

1) For the ball to reach a height 0f 40 ft, h(t) = 40, hence:

40 = -16t² + 80t + 40

16t² - 80t = 0

t(t - 5) = 0

t = 0 or t = 5

Hence it takes 5 seconds to reach a height of 40 ft.

2) The maximum height is at h'(t) = 0,

h'(t) = -32t + 80

-32t + 80 = 0

32t = 80

t = 2.5

It takes 2.5 seconds to reach maximum height.

Find out more at: brainly.com/question/11535666

5 0
3 years ago
Why isn’t there a commutative property for subtraction as well as for addition?
erma4kov [3.2K]

Answer:



Step-by-step explanation:


8 0
3 years ago
Other questions:
  • Identify the vertex and axis of symmetry of 8x<img src="https://tex.z-dn.net/?f=y%3D-x%5E%7B2%7D%20%2B8x-12" id="TexFormula1" ti
    14·1 answer
  • Consider f(x)=2x3 and g(x)=/3x-1/find each value. f(1)-g(2)
    10·1 answer
  • Solve the following using the quadratic formula:<br><br><br><img src="https://tex.z-dn.net/?f=x%5E%7B2%7D%20-%209x%20-%2045%20%3
    15·1 answer
  • Can you answer these please? Show all work
    6·1 answer
  • When simplifying 7x^0 and (7x)^0 are these the same of different?
    9·1 answer
  • 3 of 10<br>What is the 5th equivalent fraction to 2/7?​
    10·1 answer
  • 20 POINTS ILL GIVE BRAINLY TO THE FISRT ANSWER:
    8·1 answer
  • 7th grade math pls help
    13·1 answer
  • 4cos^2(65) + 4sin^2(65)<br>​
    8·1 answer
  • Find the volume of a regular cube if the length of a side is 10 cm. (Hint: V = I³.)
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!