Please I need help ;-;

Suppose a family drives at an average rate of 60 mi/h on their way to visit relatives and then an average rate of 40 mi/h on the

hammer [34]

Answer:

Part A) 2 hours

Part B) d/60 hours

Part C) 48 miles/hour

Step-by-step explanation:

Part A) Let "d" be the distance in miles the family traveled to visit their relatives. How many hours did it take to drive there?

we know that

Let

x ----> the time it take on their way to visit relatives in hours

y ---> the time it take on the way back in hours

we know that

The distance of the way to visit is equal to the distance of the way back

The speed multiplied by the time is equal to the distance

so

60x=40y -----> equation A

y=x+1 -----> equation B

substitute equation B in equation A and solve for x

60x=40(x+1)

60x=40x+40

20x=40

x=2 hours

Find the value of y

y=2+1=3 hours

d=60x

The time it take on their way to visit relatives is 2 hours

The time it take on the way back is 3 hours

Part B) In terms of "d," how many hours did it take to drive there?

we have that

The distance is equal to the speed multiplied by the time

d=60x

Solve for x

x=d/60 hours

Part C) Write and solve an equation to determine the distance the family drove to see their relatives. What was the average rate for the entire trip?

To find the average rate for the whole trip we will need the total distance and the total time

The distance of the way to visit is

d=60x

substitute the value of x

d=60(2)=120 miles

so

The total distance is

120(2)=240 miles

we know that the total time is

2 + 3 =5 hours

The average rate for the complete trip is

240/5=48 miles/hour

5 0

3 years ago

Read 2 more answers

On a floor plan for Rosedale Middle School, 1 inch represents 10 feet. If Sarah's classroom is 2 inches by 3 inches on the floor

photoshop1234 [79]

Answer:

If you want A brainly go subscribe to this youtubr channel Florida_kik

Step-by-step explanation:

3 0

2 years ago

4. A mountain climber needs to descend 2,000 feet.

DENIUS [597]

Answer:

C. 500 ft

Step-by-step explanation:

If we want to make it all equal, we can divide the 2,000 ft by 4 because we have 4 equal descents.

2000 ÷ 4 = 500

He should travel 500 feet in each descent.

8 0

2 years ago

You have been asked to design a can shaped like right circular cylinder that can hold a volume of 432π-cm3. What dimensions of t

rosijanka [135]

Answer:

$Height = 12cm$

$Radius = 6cm$

Step-by-step explanation:

Given

Represent volume with v, height with h and radius with r

$V = 432\pi$

Required

Determine the values of h and r that uses the least amount of material

Volume is calculated as:

$V = \pi r^2h\\$

Substitute 432π for V

$432\pi = \pi r^2h$

Divide through by π

$432 = r^2h$

Make h the subject:

$h = \frac{432}{r^2}$

Surface Area (A) of a cylinder is calculated as thus:

$A=2\pi rh+2\pi r^2$

Substitute $\frac{432}{r^2}$ for h in $A=2\pi rh+2\pi r^2$

$A=2\pi r(\frac{432}{r^2})+2\pi r^2$

$A=2\pi (\frac{432}{r})+2\pi r^2$

Factorize:

$A=2\pi (\frac{432}{r} + r^2)$

To minimize, we have to differentiate both sides and set $A' = 0$

$A'=2\pi (-\frac{432}{r^2} + 2r)$

Set $A' = 0$

$0=2\pi (-\frac{432}{r^2} + 2r)$

Divide through by $2\pi$

$0= -\frac{432}{r^2} + 2r$

$\frac{432}{r^2} = 2r$

Cross Multiply

$2r * r^2 = 432$

$2r^3 = 432$

Divide through by 2

$r^3 = 216$

Take cube roots of both sides

$r = \sqrt[3]{216}$

$r = 6$

Recall that:

$h = \frac{432}{r^2}$

$h = \frac{432}{6^2}$

$h = \frac{432}{36}$

$h = 12$

Hence, the dimension that requires the least amount of material is when

$Height = 12cm$

$Radius = 6cm$

3 0

3 years ago

6 in 5 in 14 in Area =

Hunter-Best [27]

Answer:

184

Step-by-step explanation:

2*(6*5+6*14+5*14)=184

3 0

3 years ago