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4 years ago

uma urna contem 7 bolas brancas, 5 bolas pretas e 4 bolas vermelhas. qual a probalidade de retirarmos, ao acaso, uma bola preta?

1 answer:

6 0

A urna contém 16 bolas no total. 5 deles são pretas.

A probabilidade de retirarmos uma bola preta é

5 / 16 = 0.3125 = 31.25% .

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Algebra 2 Math question Grade 11

Paha777 [63]

Answer:

$\displaystyle y=\frac{4}{5}x+\frac{13}{5}$

Step-by-step explanation:

The equation of the line in slope-intercept form is:

y=mx+b

Where m the slope of the line and b the y-intercept.

When two points are given, it's convenient to calculate the slope first.

Suppose we know the line passes through points A(x1,y1) and B(x2,y2). The slope can be calculated with the equation:

$\displaystyle m=\frac{y_2-y_1}{x_2-x_1}$

The points are (3,5) and (-2,1):

$\displaystyle m=\frac{1-5}{-2-3}=\frac{4}{5}$

The equation is now:

$\displaystyle y=\frac{4}{5}x+b$

To calculate b, we use any of the given points and solve for b. Use (3,5):

$\displaystyle 5=\frac{4}{5}3+b$

Operate:

$\displaystyle 5=\frac{12}{5}+b$

Solve:

$\displaystyle b=5-\frac{12}{5}=\frac{13}{5}$

The required equation of the line is:

$\boxed{\displaystyle y=\frac{4}{5}x+\frac{13}{5}}$

3 0

4 years ago

A giraffe can travel 800 feet in 20 seconds. Write a direct variation equation for the distance traveled any time | Please expla

Diano4ka-milaya [45]

The direct variation equation is:
d=kt
where d is the distance that the giraffe travels
k is the constant of variation
and t is time
Now we are told that the giraffe can travel 800 ft in 20 seconds, so we can solve for the constant of variation (k)
800=k(20) divide both sides by 20
k=40-------------and the units are ft per sec
So now we can write
d=40t
ck
d=40t
800ft=40*20 ft
800 ft= 800 ft

Hope this helps!

8 0

3 years ago

I dont get this so cant help daughter

sergey [27]

We are told that the coordinates of the image are of the formula:

P'(x-2 , y-3) where x and y are the actual points and x-2 and y-3 are the reflections

Finding the coordinates of point A:

We are given that the coordinates of reflection of A are: A'(-4 , 3)

we also know that reflected point follow the formula: P'(x-2 , y-3)

So, the points of A'(-4 , 3) follow the formula P'(x-2 , y-3)

So, their respective x and y coordinates will be equal

Hence,

x - 2 = -4

x = -2 [adding 2 on both sides]

Also,

y - 3 = 3

y = 6 [adding 3 on both sides]

Therefore, the coordinates of A are A(-2,6)

Finding the coordinates of B:

We are given the coordinates of B' are B'(-4 , 2)

So,

x - 2 = -4

x = -2 [adding 2 on both sides]

also,

y-3 = 2

y = 5 [adding 5 on both sides]

Therefore, the coordinates of B are: B(-2,5)

Finding the coordinates of C:

We are given that the coordinates of reflection of C are: C'(-2,3)

Using the general formula given in the question:

x - 2 = -2

x = 0 [adding 2 on both sides]

y - 3 = 3

y = 6 [adding 3 on both sides]

Therefore, the coordinates of C are: C(0,6)

Finally, the coordinates of A, B and C are:

A(-2,6) , B(-2,5) , C(0,6)

__________________________________________________________

Reflecting the pre-image along the x-axis

To reflect along x-axis, we multiply the y-coordinate by -1

Coordinates of the pre-image:

A(-2,6) , B(-2,5) , C(0,6)

Coordinates of points reflected along the x-axis:

A(-2,-6) , B(-2,-5) , C(0,-6)

5 0

3 years ago

HELP! FINALSS!

gladu [14]

Answer:3 1/2 ft = 7/2 ft

(7/2) 12/1 = 42 in.

Then: 42 / (5/8)

42 (8/5)

336/5

67 1/5

you can stack 67 books

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

Determine the points of intersection of the equation circumference x² + (y-3) ² = 25 with the coordinate axes.

lbvjy [14]

Answer:

(4, 0), (-4, 0), (0, -2), (0, 8)

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers