All categories

3 years ago

Can someone pls help for brainlest

Mathematics

1 answer:

tankabanditka [31]3 years ago

4 0

Answer:

1 .4&6

2.35

Step-by-step explanation:

You might be interested in

I promise I will mark as brainiest if a speed of a car increase its average speed in a journey of 200 miles by 5 mile/hour the j

jok3333 [9.3K]

Answer:

$\large \boxed{\sf \ \ \ \dfrac{\sqrt{4025}-5}{2}=29.22144... \ \ \ }$

Step-by-step explanation:

Hello

Let's note the original speed of the car v

it means that in 1 hour he is going v miles

so to go 200 miles it takes ( in hour)

$\dfrac{200}{v}$

If the speed of the car is v+5 than to go 200 miles it takes (in hour)

$\dfrac{200}{v+5}$

and this time is one hour less so we can write

$\boxed{\sf \ \ \dfrac{200}{v+5}=\dfrac{200}{v}-1 \ \ }$

We can multiply by v(v+5) both parts of the equation so

$200v=200(v+5)-v(v+5)\\\\200v=200v+1000-v^2-5v\\\\v^2+5v-1000=0$

$\Delta=b^2-4ac=5^2+4*1000=4025\\\\ \text{There are potential solutions }\\\\\ \ \ \ \ x_1=\dfrac{-5-\sqrt{4025}}{2}\\\\\ \ \ \ \ x_2=\dfrac{-5+\sqrt{4025}}{2}$

Only one is positive and this is is

$x_1=\dfrac{\sqrt{4025}-5}{2}=29.22144...$

So the original speed is 29.22144... mph

Hope this helps.

Do not hesitate if you need further explanation.

Thank you

7 0

3 years ago

1.) Michelle works at Bloomingdale's and earns a 20% commission for her daily sales. Yesterday, Michelle

laiz [17]

Answer:

$447

Step-by-step explanation:

2,235 multiplied by .20

6 0

3 years ago

Read 2 more answers

Events A and B are mutually exclusive. Also P(A) =0.2 and P(B) = 0.37. What is P(A or B)

Alchen [17]

Answer:

0.074

Step-by-step explanation:

cause in probability when two events are exclusive we use multiplication rule

7 0

3 years ago

Y=6x+20 substitution

Oksana_A [137]

Answer:

-10/3 or -3.33

Step-by-step explanation:

substitute 0 for y

0 = 6x + 20

-20 = 6x + 20 - 20 subtract 20 on both sides

-20 = 6x divide by 6 on each side

-20/6 = 6x/6

x = -20/6 simplify

x = -10/3

8 0

3 years ago

A poll asks shoppers at the mall how many cups of water they typically drink in a day. The results of the poll are listed below.

juin [17]

Answer:

D 9.5

Step-by-step explanation:

Write data in increasing order.

3, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 10, 10, 10, 10, 11

Find the median

3, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 10, 10, 10, 10, 11

Median is 8

Lower half of the data is : 3, 5, 5, 6, 6, 6, 7, 7, 8, 8,

First quartile is the median of the lower half of the data=6+6 /2 =6

Upper half of the data is: 8, 8, 8, 9, 9, 10, 10, 10, 10, 11

The Third quartile is the median of the upper half=9+10 / 2 = 9.5

3 0

3 years ago

Read 2 more answers