Answer:
15 miles
Step-by-step explanation:
Let
be the miles in the circular park path,
the time Louisa takes to finish and
the time Calvin takes to finish both in hours.
Then
, the longitude is equal to the velocity times the time used to finish. So


And the difference between Louisa's time and Calvin' time is 30 minutes, half an hour. So:

Three equations, three unknowns, the system can be solved.
Equalizing the equation with x :

In this last equation replace
with the other equation and solve:
With Louisa's time find x:
The 24th term is 152
Step-by-step explanation:
The formula of the nth term of an arithmetic sequence is:
, where
- a is the first term
- d is the common difference between consecutive terms
The third term means n = 3
∵ 
∴ 
∵
= 5
- Equate the right hand sides of the third term
∴ a + 2d = 5 ⇒ (1)
The fifth term means n = 5
∵ 
∴ 
∵
= 19
- Equate the right hand sides of the fifth term
∴ a + 4d = 19 ⇒ (2)
Now we have a system of equations to solve it
Subtract equation (1) from equation (2) to eliminate a
∴ 2d = 14
- Divide both sides by 2
∴ d = 7
- Substitute the value of d in equation (1) to find a
∵ a + 2(7) = 5
∴ a + 14 = 5
- Subtract 14 from both sides
∴ a = -9
The twenty fourth term means n = 24
∵ a = -9 and d = 7
- Substitute the values of a and d in the formula of the nth term
∴ 
∴ 
∴ 
∴ 
The 24th term is 152
Learn more:
You can learn more about the arithmetic sequence in brainly.com/question/7221312
#LearnwithBrainly
Answer:
x<20
Step-by-step explanation:
x-10<10
add 10 to both sides
x<20
X can therefore be anything less than 20.
For the first one it’s subtraction property of equality
Answer:
7 hours 30min
Step-by-step explanation:
Step one :
Given data
We are told that Erica can paint 1 room in 5hours
Her work rate is 1/5 room per hour
And also with the assistance of her friend they can paint 1 room in 3 hours
Hence their combined work rate is 1/3 room per hour
Step two
The combined work expression is
1/A+1/B=1/T
Where A=Erica's work rate
B=Rachael's work rate
T=combined work
1/5+1/B=1/3
1/B=1/3-1/5
1/B=5-3/15
1/B=2/15
B=15/2
B=7.5 hours
It will take Rachel 7 hours 30min to paint the room