How do you solve [(x+3y),(3x+y)]=[(-13),(1)]?

1 Answer
Jan 11, 2018

x=2 and y=-5

Explanation:

We can get two equations from the given:

(1) x+3y=-13
(2) 3x+y=1

If we multiply the second equation from -3 we get:
-9x-3y=-3. Adding this new equation to the first equation gives:

-8x=-16 rarr x =2.

Taking this value of x and substituting into (2) gives

3(2)+y=1 rarr6+y=1 rarry=-5,

so x=2 and y=-5