3x - 5y = 4

- 2x + 6y = 18. what is x and y

Let's isolate

x

in the first:

x

=

18

3

-

6

y

3

x

=

6

-

2

y

Now, we replace this found

x

in the second:

2

(

6

-

2

y

)

+

5

y

=

20

12

-

4

y

+

5

y

=

20

12

+

y

=

20

y

=

8

Now, you just replace this

y

=

8

in the isolated

x

above:

x

=

6

-

2

(

8

)

x

=

6

-

16

=

-

10