Question

Solve x + 3y = 9
3x – 3y = –13

Answer 1

add both the eqns
Then u get
4x=-4
divide by 4
x=-1
Substitute this in the first eqn
-1+3y=9
solve for y.

Answer 2

add 2 equations to eliminate y
solve for x
then substitute this value for x in first equation to find y

Answer 3

We can just add them together since the y-values will cancel out.
x+3y=9
3x-3y=-13
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4x=-4 Now we divide by 4 and get x=-1. Now we put this into one of the equations, doesn't matter which one it is, and solve for the y-value.
-1+3y=9 Now we add bye one to both sides.
3y=10 and now we divide by 3
y=3.33333......
So our answer is (-1,3.3...)