![issacbeecherpebpyl](/avatars/23890.jpg)
issacbeecherpebpyl
29.07.2019 •
Mathematics
Two leprechauns are arguing over a pot of gold. the first leprechaun says to the other, ‘give me seven of your gold pieces and i will have twice as many as you! ’, the other one replies, ‘no way! give me seven of yours and we’ll have the same number’. how many gold pieces does the first leprechaun have?
Solved
Show answers
More tips
- S Sport Where can you play football in Moscow?...
- F Food and Cooking 10 Reasons Why You Should Avoid Giving Re-Gifts: An Informative Guide...
- S Sport How to wrap boxing hand wraps? Everything you need to know!...
- A Animals and plants 5 Tips for Taking Care of Yews to Keep Them Green and Beautiful...
- H Health and Medicine How to Calm Your Nerves? Expert Tips That Actually Work...
- O Other What is a Disk Emulsifier and How Does it Work?...
- S Sport How to Pump Your Chest Muscle? Secrets of Training...
- C Computers and Internet How to Get Rid of 3pic Infector: Everything You Need to Know...
- S Style and Beauty How to Grow Hair Faster: Real Methods and Advice...
- C Computers and Internet How to Top Up Your Skype Account Without Losing Money?...
Answers on questions: Mathematics
- M Mathematics The awnser is 15 i did it by steep like there is 16 ones then you multiply and thye awnser i got was 15. there you go :D...
- M Mathematics Choose the TRUE statement about V85. A) It lies between 8 and 9 on a number line. B) It lies between 7 and 8 on a number line. It lies between 9 and 10 on a number line....
- C Computers and Technology #Write a function called get_grade that will read a #given .cs1301 file and return the student s grade. #To do this, we would recommend you first pass the #filename...
- E English Help it easy help i need it dont lie or get reported...
- M Mathematics Which point lies in the area defined by the following system of inequalities? 2x – y ≤ - 3 3x + 2y 11...
Ответ:
Gold pieces the second leprechaun has: y
The first leprechaun says to the other, ‘Give me seven of your gold pieces and I will have twice as many as you!’:
The first leprechaun would have x+7
The second leprechaun would have y-7
I will have twice as many as you:
(1) x+7=2(y-7)
(1) x+7=2y-14
(1) x+7-7-2y=2y-14-7-2y
(1) x-2y=-21
The other one replies, ‘No way! Give me seven of yours and we’ll have the same number’
The first leprechaun would have x-7
The second leprechaun would have y+7
We’ll have the same number:
(2) x-7=y+7
(2) x-7+7-y=y+7+7-y
(2) x-y=14
How many gold pieces does the first leprechaun have?
x=?
We have a system with 2 equations and two unknows (x and y). We need to solve for x:
(1) x-2y=-21
(2) x-y=14
Using the method of substitution, we can isolating y in the second equation:
(2) x-y=14
(2) x-y+y-14=14+y-14
(2) x-14=y
(2) y=x-14
And we can replace y in the first equation by x-14, and solve for x:
(1) x-2y=-21
(1) x-2(x-14)=-21
(1) x-2x+28=-21
(1) -x+28=-21
(1) -x+28-28=-21-28
(1) -x=-49
(1) (-1)*(-x=-49)
(1) x=49
The first leprechaun has 49 gold pieces
Ответ: