Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Trig help! 10 pts best answer!?
We are working on solving systems using the method of elimination. There are three problems that I'm confused on because they involve fractions. If you could please show me how to solve each problem it would be greatly appreciated! Include all of your work too please. And I know this is a lot of work so there will be a best answer chosen! Thanks!
x/4 + y/6 = 1
x - y = 3
(x+3)/4 + (y-1)/3 = 1
2x - y = 5
(x-1)/2 + (y+2)/3 = 4
x - 2y = 5
Never mind! Something just clicked in my brain and I solved them all! Thanks anyway!
3 Answers
- AriLv 61 decade agoFavorite Answer
1. u can use substitution
x/4 + y/6 = 1
x - y = 3
multiply top equation by 12 to clear the fractions
3x + 2y = 12
x - y = 3
multiply bottom by 2
3x + 2y = 12
2x -2y = 6
add
5x = 18
x = 18/5.
and therefore x = 3+y --> 18/5 = 3 + y --> y = 3/5
2.
(x+3)/4 + (y-1)/3 = 1
2x - y = 5
multiply the top eq. to clear fractions
3(x+3) + 4 (y-1) = 12
2x - y = 5
expand
3x+9 + 4y -4 = 12
3x + 4y = 7
2x - y = 5
multiply bottom eq. by 4'
3x + 4y = 7
8x - 4y = 10
11 x = 70
x = 70/11.
since 2x-y = 5 --> 140/11 -y = 5 --> y =85/11
- ?Lv 41 decade ago
Your first system is below. To clear the fractions lets multiply the top equation by 12. This has nothing to do with solving for the solution but to get rid of the denominators. I do so we get
12(x/4 + y/6 = 1)
x - y = 3
3x + 2y = 12
x - y = 3
Multiply second equation by 2 and add to the first equation and we get
3x + 2y = 12
2x - 2y = 6
5x = 18
x = 18/5 and to find plug this into either of the original equtions and solve for y. Let's chose the second equation and we get
18/5 - y = 3
- y = - 3/5
y = 3/5 so your solution is (18/5, 3/5)
Problem 2
Just like first problem multiply top equation by 12 to clear fractions and we get
12((x+3)/4 + (y-1)/3 = 1)
2x - y = 5
3(x + 3) + 4(y - 1) = 12
2x - y = 5
3x + 9 + 4y - 4 = 12
2x - y = 5
3x + 4y = 7
2x - y = 5
Multiply second equation by 4 and add to first eqation and we get
3x + 4y = 7
8x - 4y = 20
11x = 27
x = 27/11 now plug this back into either of the original equations and solve for y. Use second equation and we get
2(27/11) - y = 5
54/11 - y = 5
- y = 55/11 - 54/11
- y = 1/11
y = - 1/11 so the solution is (27/11, - 1/11)
The last system multiply the first equation by 6 to clear fractions
6((x-1)/2 + (y+2)/3 = 4)
x - 2y = 5
3(x - 1) + 2(y + 2) = 24
x - 2y = 5
3x - 3 + 2y + 4 = 24
x - 2y = 5
3x + 2y = 23
x - 2y = 5
Just add the equations and we get
4x = 28
x = 7 and substituting back into one of the original equations. Lets chose the second and we get
7 - 2y = 5
- 2y = - 2
y = 1 and the solution is (7,1)
- 1 decade ago
ok so for the first one
x/4 + y/6 = 1
x - y = 3
so you want to solve for something first
x - y = 3
x= 3 + y
so then you plug it into the other equation
x/4 + y/6 = 1
(3+y)/4+y/6 = 1
then you need to add the to fractions
6(3-y)/24 + 4y/24 = 1
(18 + 6y + 4y )/ 24 = 1
(18 + 10y) = 24
10y = 6
y = 3/5
x - y = 3
x - (3/5) = 3
x = 18/5
