Question

Why can't I get this?? Please help..
What is the solution of the system?
y=-3x
3x + 2y=6

Answer 1

well, they tell you y = - 3x, what do we do with that?

Answer 2

solve for 2 coordinates using elimination

Answer 3

substitution would be a simple process is what im thinking

Answer 4

How do I even come up with an answer to this? x and y?

Answer 5

well, they tell you that y = -3x, so everywhere you see a y, replace it by -3x; would be a start

Answer 6

I came up with -2 and 6 but im so confused on what the heck to do

Answer 7

3x + 2y=6

3x + 2(-3x)=6

the rest is like the most basic algebra to solve for x

Answer 8

lets see if -2, 6 fits ..

6=-3(-2) good
3(-2) + 2(6)=6
-6 + 12 = 6 good

nothing else to do .. you solved it

Answer 9

Ok so using substitution we plug those in and show they are correct and thank you so much for your help I get so dang confused

Answer 10

youre welcome :) im going home for now so good luck

Answer 11

thanks!

Answer 12

if you know the answer, you can test that the answer works, as amiste did up above.

If you don't know the answer, you have to do algebra.
y=-3x
3x + 2y=6

the first equation says y is the same thing as -3x (-3 times x)
if you replace y in the 2nd equation with -3*x you get
3x +2(-3x) = 6

that means 3 * x + 2*-3*x = 6

2*-3 is -6 so we can simplify to
3x -6x = 6

3 x's take away 6 x's leaves -3 x's or -3x
-3x = 6

divide both sides by -3

-3x/-3 = 6/-3

-3/-3 is 1 so
1*x = 6/-3

or
x= 6/-3

6 divided by -3 is -2
x= -2