Hey! a+5=7 means that a is the variable, while seven is the answer. My technique is like this: 7-5=2 You need to subtract the numbers you already have. This only works for addition! Hope this helps :) !
Answer: He needs 9 hours to finish the task.
Step-by-step explanation:
Hi, first we have to subtract the gallons of water already in the tank (75) to the total capacity of the tank (300).
300-75 = 225
He needs to fill 225 gallons.
Since the pump Ross uses can fill 25 gallons of water per hour, the proportion is :
25 g / 1h
For 225 gallons:
225 g / x hours
Solving for x
25/1 = 225/x
x= 225/ (25/1)
x = 9 hours
Answer:
factoring: (
3
x
+
1
)
(
3
x+
2
)
expressing/equation: 9x²= 81x
81x + 9x + 2=
9x+81x=90x
90x + 2
Step-by-step explanation:
Answer:
228.4
Step-by-step explanation:
9.2 + 9.2 + 60 + 75 +75 which is 228.4. Remember to divide the triangles by two after you do base times height.
Option 1:
<span>Measuring the heights of every fiftieth person on the school roster to determine the average heights of the boys in the school
</span>
Comment: this might not be a good idea for fairness as we only wish to determine average height of the boys. Taking a group of 50 people randomly, might not give us the same number of boys every time.
Option 2:
<span>Calling every third person on the soccer team’s roster to determine how many of the team members have completed their fundraising assignment
Comment: The context doesn't seem to need a sampling. The number of players in a soccer team is considerably small. We can find exact data by asking in person.
Option 3:
</span><span>
Observing every person walking down Main Street at 5 p.m. one evening to determine the percentage of people who wear glasses
</span>
Comment: To get a more accurate result and fairer sampling, the period of observing could have been longer, for example, observing for 12 hours on that day, or an alternative is to observe at 5 pm for 7 days in a row. It could happen that no one walking down the Main street precisely at 5 pm wears glasses, or it could happen the other way around.
Option 4:
<span>Sending a confidential e-mail survey to every one-hundredth parent in the school district to determine the overall satisfaction of the residents of the town taking a poll in the lunch room (where all students currently have to eat lunch) to determine the number of students who want to be able to leave campus during lunch.
Comment: This sampling does fairly represent the population, although it might be an idea to scale down the sample population, i.e. every fiftieth parent.
Answer: Option 4</span>
