All categories

2 years ago

Choose the solutions to the quadratic equation x2 – 8x – 9 = 0. –21 –1 9 29

Mathematics

1 answer:

8090 [49]2 years ago

6 0

Answer:

-1 and 9

Step-by-step explanation:

To solve the quadratic, factor and set its factors equal to 0. Factoring is the action of breaking up a polynomial into pieces which multiply to make it. The factors are found by multiplying numbers to make C and add to B of $ax^2+bx+c$ .

Here c = -9 and b = -8. The numbers -9 and 1 multiply to -9 and add to -8. These are the factors (x-9)(x+1).

Set each equal to 0 and solve for x.

x-9 = 0

x = 9

x+1 =0

x = -1

You might be interested in

In a recipe for fizzy grape juice, the ratio of cups of sparkling water to cups of grape

Ierofanga [76]

ummm well thats a good question

Step-by-step explanation: hold on let me think

3 0

2 years ago

Locate the points of discontinuity in the piecewise function shown below.

algol13

Answer:

Step-by-step explanation:

The given piecewise function i

From the given function it is clear that function is divided at x=-1 and x=2. It means we check the discontinuity at x=-1 and x=2.

For x=-1,

LHL:

Since LHL ≠ f(-1), therefore the given function is discontinuous at x=-1.

For x=2,

LHL:

Since LHL ≠ f(2), therefore the given function is discontinuous at x=2.

Therefore, the correct option is A.

8 0

2 years ago

Alex repairs clocks at a shop.· He earns $96 per day plus $16 per hour for every hour of overtime he works.· Each day, he wants

shutvik [7]

T=16x+96 so if he wants to receive 130$ a day he must work at least 3 hours of over time.

7 0

2 years ago

Read 2 more answers

On a standardized test with a normal distribution the mean score was 67.2. The standard deviation was 4.6. What percent of the d

Reika [66]

Answer:

P ( -1 < Z < 1 ) = 68%

Step-by-step explanation:

Given:-

- The given parameters for standardized test scores that follows normal distribution have mean (u) and standard deviation (s.d) :

u = 67.2

s.d = 4.6

- The random variable (X) that denotes standardized test scores following normal distribution:

X~ N ( 67.2 , 4.6^2 )

Find:-

What percent of the data fell between 62.6 and 71.8?

Solution:-

- We will first compute the Z-value for the given points 62.6 and 71.8:

P ( 62.6 < X < 71.8 )

P ( (62.6 - 67.2) / 4.6 < Z < (71.8 - 67.2) / 4.6 )

P ( -1 < Z < 1 )

- Using the The Empirical Rule or 68-95-99.7%. We need to find the percent of data that lies within 1 standard about mean value:

P ( -1 < Z < 1 ) = 68%

P ( -2 < Z < 2 ) = 95%

P ( -3 < Z < 3 ) = 99.7%

6 0

2 years ago

If y varies directly as x and y = 24 when<br> x= 16, what is y when x = 50? PLEASE ANSWER ASAP!!!!

11111nata11111 [884]

Answer:

$y = 75$

Step-by-step explanation:

Given

$y\ \alpha\ \ x$

$y=24; x =16$

Required

Find y when $x = 50$

We have:

$y\ \alpha\ \ x$

Express as equation

$y = kx$

Solve for k

$k = \frac{y}{x}$

When $y=24; x =16$

$k = \frac{24}{16}$

$k = \frac{3}{2}$

When $x = 50$ , we have:

$y = kx$

$y = \frac{3}{2} * 50$

$y = 75$

6 0

2 years ago