235 x 26 = estimate the answer

Which of the following choices evaluates -2x2 + 4x, when x = -2?

sammy [17]

Answer:

x = -2

-2(-2^2) + 4(-2)

-2(4) + -8

<h2>-8 + -8</h2><h2><em><u>Answer = -16 is the answer.</u></em></h2>

5 0

3 years ago

In the xy-plane, the line k passes through the origin and through the point (a,b), where ab ≠ 0. Is b positive? (1) The slope of

Vadim26 [7]

Answer:

Yes

Step-by-step explanation:

Since the line passes through the origin, when calculating the slope of the line, we can make use of the origin as a point. So pests say (x1, y1) = (0,0) and (x2,y2) is (a,b). Hence the slope is b/a.

Now we now act on this information to solve the problem. Firstly, we know that the slope is negative, this means either a or b is negative but both are not negative. Secondly, b is greater than a. This mean b is the positive term as both terms cannot be negative.

6 0

4 years ago

Use the functions a(x)=4x+9 and b(x)=3x-5 to complete the function operations listed below. Part a: find (a+b)(x) show your work

ddd [48]

Parts a and b are straight-forward. You add them in part a: 4x + 9 + 3x - 5 and you get 7x + 4. For part b, you are multiplying them (4x + 9)(3x - 5) by FOILing them: $12 x^{2} -20x+27x-45$ which simplifies to $12 x^{2} +7x-45$
The last one is a composite; you are told to find a of b of x. The way you do that is to take your inside function and put that whole function into the other function every place you see an x, like this:
a(b(x))= 4(3x-5) + 9. Now distribute the 4 into the parenthesis to get 12x - 20 + 9, which simplifies to 12x - 11. And that's it!

5 0

3 years ago

HELP PLZ <br> i need help with this math side i just need b,c,d a =4x+2y=16

tino4ka555 [31]

Answer:

Please check the explanatio.

Step-by-step explanation:

Solving Part b)

We know that the slope-intercept form of the equation line is

$y=mx+b$

where m is the slope and b is the y-intercept

Given the equation

$4x+2y=16$

Re-writing the equation in the slope-intercept form

$4x+2y=16$

$y=-2x+8$

Here, m=-2 and b=8

Thus, the equation in the slope-intercept form will be:

$y=-2x+8$

Solving Part c)

As you sold two pounds of cheddar cheese.

i.e. y=2

substituting y=2 in the slope-intercept form of the line equation

$y=-2x+8$

$2=-2x+8$

Subtract 8 from both sides

$-2x+8-8=2-8$

$-2x=-6$

Divide both sides by -2

$\frac{-2x}{-2}=\frac{-6}{-2}$

$x=3$

You sold 3 pounds of swiss cheese.

Solving Part d)

$y=-2x+8$

putting x=2.5 in the equation

$y=-2x+8$

$2=-2\left(2.5\right)+8$

$2=3$

The sides are not equal

<em>FALSE</em>

Thus, x=2.5 does not make any sense in the context of the problem.

6 0

3 years ago

In the following problem, check that it is appropriate to use the normal approximation to the binomial. Then use the normal dist

Marrrta [24]

Answer:

a) Bi [P ( X >=15 ) ] ≈ 0.9944

b) Bi [P ( X >=30 ) ] ≈ 0.3182

c) Bi [P ( 25=< X =< 35 ) ] ≈ 0.6623

d) Bi [P ( X >40 ) ] ≈ 0.0046

Step-by-step explanation:

Given:

- Total sample size n = 745

- The probability of success p = 0.037

- The probability of failure q = 0.963

Find:

a. 15 or more will live beyond their 90th birthday

b. 30 or more will live beyond their 90th birthday

c. between 25 and 35 will live beyond their 90th birthday

d. more than 40 will live beyond their 90th birthday

Solution:

- The condition for normal approximation to binomial distribution:

n*p = 745*0.037 = 27.565 > 5

n*q = 745*0.963 = 717.435 > 5

Normal Approximation is valid.

a) P ( X >= 15 ) ?

- Apply continuity correction for normal approximation:

Bi [P ( X >=15 ) ] = N [ P ( X >= 14.5 ) ]

- Then the parameters u mean and σ standard deviation for normal distribution are:

u = n*p = 27.565

σ = sqrt ( n*p*q ) = sqrt ( 745*0.037*0.963 ) = 5.1522

- The random variable has approximated normal distribution as follows:

X~N ( 27.565 , 5.1522^2 )

- Now compute the Z - value for the corrected limit:

N [ P ( X >= 14.5 ) ] = P ( Z >= (14.5 - 27.565) / 5.1522 )

N [ P ( X >= 14.5 ) ] = P ( Z >= -2.5358 )

- Now use the Z-score table to evaluate the probability:

P ( Z >= -2.5358 ) = 0.9944

N [ P ( X >= 14.5 ) ] = P ( Z >= -2.5358 ) = 0.9944

Hence,

Bi [P ( X >=15 ) ] ≈ 0.9944

b) P ( X >= 30 ) ?

- Apply continuity correction for normal approximation:

Bi [P ( X >=30 ) ] = N [ P ( X >= 29.5 ) ]

- Now compute the Z - value for the corrected limit:

N [ P ( X >= 29.5 ) ] = P ( Z >= (29.5 - 27.565) / 5.1522 )

N [ P ( X >= 29.5 ) ] = P ( Z >= 0.37556 )

- Now use the Z-score table to evaluate the probability:

P ( Z >= 0.37556 ) = 0.3182

N [ P ( X >= 29.5 ) ] = P ( Z >= 0.37556 ) = 0.3182

Hence,

Bi [P ( X >=30 ) ] ≈ 0.3182

c) P ( 25=< X =< 35 ) ?

- Apply continuity correction for normal approximation:

Bi [P ( 25=< X =< 35 ) ] = N [ P ( 24.5=< X =< 35.5 ) ]

- Now compute the Z - value for the corrected limit:

N [ P ( 24.5=< X =< 35.5 ) ]= P ( (24.5 - 27.565) / 5.1522 =<Z =< (35.5 - 27.565) / 5.1522 )

N [ P ( 24.5=< X =< 25.5 ) ] = P ( -0.59489 =<Z =< 1.54011 )

- Now use the Z-score table to evaluate the probability:

P ( -0.59489 =<Z =< 1.54011 ) = 0.6623

N [ P ( 24.5=< X =< 35.5 ) ]= P ( -0.59489 =<Z =< 1.54011 ) = 0.6623

Hence,

Bi [P ( 25=< X =< 35 ) ] ≈ 0.6623

d) P ( X > 40 ) ?

- Apply continuity correction for normal approximation:

Bi [P ( X >40 ) ] = N [ P ( X > 41 ) ]

- Now compute the Z - value for the corrected limit:

N [ P ( X > 41 ) ] = P ( Z > (41 - 27.565) / 5.1522 )

N [ P ( X > 41 ) ] = P ( Z > 2.60762 )

- Now use the Z-score table to evaluate the probability:

P ( Z > 2.60762 ) = 0.0046

N [ P ( X > 41 ) ] = P ( Z > 2.60762 ) = 0.0046

Hence,

Bi [P ( X >40 ) ] ≈ 0.0046

4 0

4 years ago