Homework help: use elimination to solve each system of equations?

Question

-5x + 3y= 6
x-y=4

If you would like your answer to be picked as the best answer, please do the following:

Please include all work

Please give steps on how you've completed it

Please give tips

Please give final answer in coordinates

Answer 1

-5x + 3y = 6 ---(1)
x - y = 4----(2)
3x(2)
3x - 3y = 12 ---(3)
(1) + (3)
-2x = 18
x = -9
subsititute into (2)
-9 - y = 4
y = -13
(-9,-13)

Answer 2

first pick out a variable you want to eliminate. let's go with y.

so multiply the bottom equation by 3 that way, the y's cancel out.

so...
-5x+3y=6
3(x-y)=3(4)

-5x+3y=6
3x-3y=12

so when you add the bottom from the top, you get...

-2x=18
x=-9

plug x back in.

-9-y=4
-y=5
y=-5

(-9,-5)

Answer 3

-5x+3y=6
3x-3y=12
adding
-2x=18
x=-9
sub in -5x+3y=6
45+3y=6
3y=39
y=13
soln.set(-9,13)