Question

What is the value of the y variable in the solution to the following system of equations?
13x - 6y = 20
7x + 4y = 18

2

1

-2

-1

Answer 1

13x - 6y = 20.............i
7x + 4y = 18.............ii

Answer 2

Now,
(20+6y)/13=(18-4y)/7

Answer 3

Now, substitute all the values and see which one satisfies

Answer 4

Does it help?

Answer 5

Do you still need help with this problem? :)

Answer 6

Isolate both x's and use x1= x2 to solve for y

Answer 7

i got y = -2 - .6 :/

Answer 8

you guys did it a very complicated way^ i still don't understand..

Answer 9

Multiply both sides of 13x - 6y = 20 by 2 to get


13x - 6y = 20

2(13x - 6y) = 2*20

26x - 12y = 40


Multiply both sides of 7x + 4y = 18 by 3 to get


7x + 4y = 18

3(7x + 4y) = 3*18

21x + 12y = 54


So we now have the system

26x - 12y = 40
21x + 12y = 54

Answer 10

Add the equations

26x - 12y = 40
21x + 12y = 54
---------------
47x = 94

and solve for x

47x = 94

x = 94/47

x = 2

Answer 11

Haha, I was too lazy to write all that.

Answer 12

then use this to find y

13x - 6y = 20

13(2) - 6y = 20

26 - 6y = 20

-6y = 20 - 26

-6y = -6

y = -6/(-6)

y = 1

Answer 13

Oh i understand better now, why did you multiply both sides by 2 in the first step? how did you get that number. i didn't know you had to add the equations together either.

Answer 14

lol c=

Answer 15

that is called elimination. we use this method to eliminate either x or y. Since you wanted the y value of the system, he eliminated your x

Answer 16

I will post a couple of examples for you