Keisha has 45 coins in her piggy bank, consisting of only nickels, dimes and quarters. She has one fewer nickel than she has dimes, and one fewer quarter than three times her number of nickels. How many nickels does she have?
Answer:
20 nickels, 40 dimes, and 8 quarters
Step-by-step explanation:
This is a system of three equations with three unknowns. Let x = # of nickels, y = # of dimes, and z = # of quarters.
x + y + z = 68 (since there are 68 total coins)
.05x + .10y + .25z = 7
.10x + .05y + .25z = 6 (if the nickels were dimes and the dimes were nickels)
Multiply both sides of the last two equations by 100 to simplify, giving us:
5x + 10y + 25z = 700 or x + 2y + 5z = 140 if you divide both sides by 5.
10x + 5y + 25z = 600 OR 2x + y + 5z = 120 if you divide both sides by 5.
Let's solve the first equation for x. That gives us x = 68 - y - z. We can substitute this result into each of the final two equations to create a system of two equations with two unknowns, which is easier to solve. For the first equation:
(68 - y - z) + 2y + 5z = 140
68 + y + 4z = 140 or y + 4z = 72
For the second equation, we have:
2(68 - y - z) + y + 5z = 120
136 - 2y - 2z + y + 5z = 120
136 - y + 3z = 120
-y + 3z = -16
Now we have our system of two linear equations:
y + 4z = 72
-y + 3z = -16
If we add those two equations together, then we get 7z = 56 or z = 8. If z = 8, we can substitute this into either of the two previous equations. Let's choose the first. This gives us:
y + 4(8) = 72 or y + 32 = 72.
So y = 40. If y = 40 and z = 8, then we know:
x = 68 - y - z = 68 - 40 - 8 = 28 - 8 = 20.
Consequently, there were 20 nickels, 40 dimes, and 8 quarters in the piggy bank.
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i HATE this mathhhhhhhhhhhhhhh
Answer: 10
Step-by-step explanation: 12 divided by 2 is 6 plus 4 is 10
Two members of a band want to get word out about their next gig. Jack's plan is that he can pass out 100 fliers a day. Meg has a different strategy. She wants to tell each of her friends about the performance on the first day, and ask each of her 10 friends to each tell a friend on the second day, and then everyone who has heard about the concert would tell a friend on the third day, and so on. Meg's idea can be modeled with the function M(t)=10(2)^2-1, where t is the number of days.
Which plan would work out better in 7 days? What about 5, 8, 9, and 300 days?
Answer:b. Multiple pigments absorb different wavelengths of light, allowing the plant to capture the maximum amount of energy from the sun.
Step-by-step explanation:
An electronics company refurbishes ink-jet printers.
The table shows the revenue produced for the number of units sold.
How much revenue will be produced for 45 units?
a-$20,000
b-$2,000
c-$15,500
d-$1,550
60 POINTS AND BRAINLY
Select the correct answer from the drop-down menu.
The value from the set {10, 11, 12, 13} that makes the equation 2(x − 5) = 12 true is (blank).
Answer:
11
Step-by-step explanation:
Multiply the parenthesis
2*x = 2x
2*5 = 10
2x-10 = 12
Because we subtract 10 to get 12, we add 10 to see the 2x
12+10 = 22
Now 2x = 22
2x=22
2x / 2 = 22 / 2
x=11
Answer:
i have brainly but it is 11
Step-by-step explanation:
if january 1st was on a tuesday, on what day of the week would february 1 fall?
Answer:
In America it would be a Monday.
Step-by-step explanation:
It matters where you live.
can you um help me wth these plese
Answer:
2. 7+15x9x9=277
3. 220-450/3x3=170
Step-by-step explanation:
PEMDAS
2. 9x9=81
15x18=270
270+7=277
3. 3x3=9
450/9=50
220-50=170
Chris has finished 30% of an art project that has taken him a total of 9 hours so far. If he continues to work at the same rate, how many hours will it take for him to complete the entire project?
If Chris has finished 30% of an art project in 9 hours then he will take 30 hours to complete the whole work if he will work at same rate.
What is rate?A measure, quantity, or frequency, typically one measured against some other quantity or measure.
How to calculate time?Let the project contains 100 questions in total.
Chris finished 30% questions so he may finish 30 questions in 9 hours.
So in order to complete the 1 question he took =9/30 hours
In order to complete 100 questions he will take 9/30*100 hours which is equal to 30 hours.
Hence Chris will take 30 hours to complete the project.
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help ?//////////////
Find the value of x in the figure
PLEASE HELP, WILL MARK BRAINLIEST!! <3
Joanna is driving 185 miles to visit her family. She drives 68 miles in the morning, stops for lunch, and then drives the rest of the distance. How many miles did she drive after lunch?
Use the variable m to represent the number of miles she drove after lunch.
Which equation represents this situation and its solution?
A. m + 68 = 185; m = 117
B. 185m = 68; m = 17
C. 68m = 185; m = 17
D. m + 185 = 68; m = 117
Answer:
I believe the answer is A. m + 68 = 185; m = 117
Step-by-step explanation:
Caitlyn ran a 400-meter race in 68 seconds. Assuming her pace was constant, how long did it take her to run 1 meter?
Answer:
.17 seconds
Step-by-step explanation:
I divided 68 by 400
Determine if the work for the problem below is correct. Correct any errors and explain your thinking.
Need help will try to give as much points
Answer:
[tex]{21}y^{2} - 63[/tex]
can u help me here please? i need to show my work :(
Answer:
u could use desmos. it works with these things
Step-by-step explanation:
do u ever just feel brain dead??? just me? ight cool
which is more a gram or kilogram??
Answer:
me all the time wanna be friends?
Answer:
gram and yes i do
Step-by-step explanation:
Can someone help with my math
Answer:
220 yards
Step-by-step explanation:
Answer: 220 yards
Step-by-step explanation:
I hope this helps!
Jamal owns a parking garage and is trying to find the relationship between hour of the day and number of cars in the garage. He finds that between 4 am and 10 am he can model this with a linear relationship. The equation for this model is y = 3.96x + 2. How many cars were in the garage at 4 am.
A) 1
B) 2
C) 3
D) 4
Jamal owns a parking garage and is trying to find the relationship between hour of the day and number of cars in the garage. He finds that between 4 am and 10 am he can model this with a linear relationship. The equation for this model is y = 3.96x + 2. How many cars were in the garage at 4 am.
A) 1
B) 2
C) 3
D) 4
The distance between Oakdale and Pine City is 200 mi. If a train is traveling at a constant rate of 50 mph, how long will it take for the train to travel from Oakdale to Pine City?
A. 4 hr.
B. 6 hr.
C. 10 hr.
D. 20 hr.
Answer:
4 hours
Step-by-step explanation:
200 divided by 50 equals 4
Answer:
If the distance between those places is 200 miles and we're travelling at 50 miles per hour (what it means mph), we can divide, as we know the kilometers we need to do to arrive and the ones we do per hour
200/50 = 4
And we get 4 hours..
Of the 480 visitors on Saturday, 60% of them stayed until the park closed. About how many visitors stayed until the park closed?
Answer:
288 visitors stayed
Step-by-step explanation:
Which of the following statements describes the process for solving -3x ≥ 18?
Divide both sides of the inequality by 18 and flip the symbol.
Divide both sides of the inequality by -3 and don't flip the symbol.
Divide both sides of the inequality by -3 and flip the symbol.
Divide both sides of the inequality by 18 and don't flip the symbol.
Answer:
the correct answer is C
Step-by-step explanation:
The correct option is 3) Divide both sides of the inequality by -3 and flip the symbol.
What is an inequality?An inequality is an inequation separated by <,>≥,≤
Given here, -3x≥18
Dividing both sides by -3 and reversing the inequality we get
x≤-6
Hence Option 3) is correct answer
Learn more about the inequality here:
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275 students and teachers take a train trip to the Grand Canyon if one train car holds 75 people, how many train cars will it take for the whole group?
Answer:
796
Step-by-step explanation:
Answer:
4
Step-by-step explanation:
the total number of people is 275 and each train car holds 75 people so you divide 275 by 75 and you get 3.6666. so you round up and you 4
Which one is the correct answer? And please show me the work you did
can somebody please help im stuck on it :(
Answer:
G
Step-by-step explanation:
It is the same equation but backward
help me wiLL GIVE BRAINLESIT
Answer:
A.
Step-by-step explanation:
If you would take a look at the chart you would see how the decimals in y are going up by .5
Please help-
When Bonita started driving at 4:00 P.M., the temperature was 12°F. When she arrived at home at 10:00 P.M., the temperature was -5°F. What was the change in temperatures from 4:00 P.M. to 10:00 P.M.?
Answer:
17°f
Step-by-step explanation:
it might be right...it seems to easy though so I'm not sure
please help with math! Giving a thanks
Answer:0.75c
Step-by-step explanation:
If Kendall walks at a steady pace of 3 mph, how long will it take her to walk 9 mi.?
A. 1 hr.
B. 2 hr.
C. 3 hr.
D. 4 hr.
Answer:
c
Step-by-step explanation:
3x3 equals 9 so it will take 3 hrs to walk
helpppppp meeeeee -__-
Answer:
im so confused
Step-by-step explanation:
Answer:
1. 5:2
2. 10:7
3. 13:10
4. 50: 47
Step-by-step explanation:
sorry but I think this is right