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3 years ago

Let k(x)=3x+7 and n(x)=-5x - 8 , find n(k(x)).

Mathematics

2 answers:

cricket20 [7]3 years ago

5 0

Answer:

Step-by-step explanation:

jarptica [38.1K]3 years ago

4 0

Answer:

its C

Step-by-step explanation:

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Starting at home, Luis traveled uphill to the gift store for 50 minutes at just 6 mph. He then traveled back home along the same

mario62 [17]

Average speed for the entire trip, both ways, is

   (Total distance) divided by (total time) .

We don't know the distance from his house to the gift store,
and we don't know how long it took him to get back.
We'll need to calculate these.

-- On the trip TO the store, it took him 50 minutes, at 6 mph.
-- 50 minutes is 5/6 of an hour.
-- Traveling at 6 mph for 5/6 of an hour, he covered 5 miles.
-- The gift store is 5 miles from his house.
-- The total trip both ways was 10 miles.

-- On the way BACK home from the store, he moved at 12 mph.
-- Going 5 miles at 12 mph, it takes (5/12 hour) = 25 minutes.

Now we have everything we need.

Distance:
   Going:    5 miles
   Returning: 5 miles
   Total    10 miles

Time:
   Going:    50 minutes
   Returning:   25 minutes
   Total:    75 minutes = 1.25 hours

   Average speed for the whole trip =

   (total distance) / (total time)

   = (10 miles) / (1.25 hours)

   = (10 / 1.25) miles/hours

   = 8 miles per hour

4 0

3 years ago

Washing his dad's car alone, eight-year-old Levi takes 2.5 hours. If his dad helps him, then it takes 1 hour. How long does it t

Dmitry [639]

Answer:

Levi's dad takes 1.67 hours to wash the car by himself

Step-by-step explanation:

* Lets explain how to solve the problem

- Levi takes 2.5 hours to wash his dad's car alone

- Levi and his dad take 1 hour to wash the dad's car together

∵ Levi takes 2.5 hours to wash the car alone

∴ The rate of Levi is 1/2.5 car/hr

∵ His dad takes x hours to wash the car alone

∴ The rate of his dad is 1/x car/hr

∵ They working together for 1 hour to wash the car

- The equation of the work is rate of Levi × t + rate of his dad × t = 1

∵ t is the time of working together

∵ t = 1 hour

∴ $\frac{1}{2.5}(1)+\frac{1}{x}(1)=1========\frac{1}{2.5}+\frac{1}{x}=1$

- Multiply both sides by 2.5x to cancel the denominators

∵ $\frac{1}{2.5}(2.5x)=x=====\frac{1}{x}(2.5x)=2.5$

∵ 1 × (2.5x) = 2.5x

∴ x + 2.5 = 2.5x

- Subtract x from both sides

∴ 2.5 = 1.5x

- Divide both sides by 1.5

∴ x = 5/3 ≅ 1.67

∵ x is the the time of his dad to wash the car alone

∴ Levi's dad takes 1.67 hours to wash the car by himself

3 0

3 years ago

Read 2 more answers

A spherical balloon has a circumference of 25 cm.

ArbitrLikvidat [17]

Answer:

See below ↓↓

Step-by-step explanation:

Finding the radius

C = 2πr
25 = 2 x 3.14 x r
r = 25 / 6.28
r = 3.98 cm ≅ 4 cm

Surface Area

4πr²
4 x 3.14 x 4 x 4
3.14 x 64
200.96
201 cm²

Volume

4/3πr³ = 4πr² x r/3
201 x 4/3
67 x 4
268 cm³

4 0

2 years ago

Please help me, will mark!!

BabaBlast [244]

Answer:

613 meters

Step-by-step explanation:

cos(50 degrees)=324/x

x*cos(50 degrees)=324

x=324/cos(50 degrees)

x=around 504.1

cos(35 degrees)=324/x

x*cos(35 degrees)=324

x=324/cos(35 degrees)

x=around 395.5

now lets find the distance in between the two people:

Distance from Shively to the tower

tan(50 degrees)=x/324

x=324*tan(50 degrees)

x= around 386.1

Distance from Sparzak to the tower

tan(35 degrees)=x/324

x=324*tan(35 degrees)

x=around 226.9

total distance=386.1+226.9=613 meters

8 0

3 years ago

A bag contains only red and blue marbles. Yasmine takes one marble at random from the bag. The probability that she takes a red

mamaluj [8]

Let red marbles = X.

The probability is 1 out of 5, written as 1/5

1/5 in terms of red marbles is equal to the number of red marbles divided by 5x, where 5x is the total number of marbles.

1/5 = x/5x

Now you have 5x total marbles, x red and 4x blue.

Add 5 more red and the new probability is:

(x+5)/(5x+5) = 1/3

Simplify:

3x+15 = 5x+5

Now solve for x:

Subtract 3x from both sides:

15 = 2x +5

Subtract 5 from each side:

2x = 10

Divide both sides by 2:

x = 10/2

X = 5

There were originally 5 red marbles.

5 0

3 years ago