solving system of equations?

Question

3x+3y=-3
2x+1y=-6

Answer 1

3x+3y=-3
2x+1y=-6 ----> y = -6 - 2x

3x + 3(-6 - 2x) = -3
3x + (-18 -6x) = -3
3x - 6x - 18 = -3
-3x = 15
x = -5

y = -6 - 2x = -6 -2(-5) = -6 - (-10) = 4

x = -5, y = 4

Answer 2

3x+3y=-3
2x+1y=-6

Multiply "-2" on the top, and multiply "3" on the bottom, so you could get rid of "x"

(-2) 3x+3y=-3
(3) 2x+1y=-6

multiply "-2" by every number, after that multiply "3" by every number

-6x-6y=6
6x+3y=-18

Get rid of "x", add -6 and 3 together, then add -18 and 6 together. It should look like this: get "y" by itself, by dividing -3 to the other side.

-3y=-12
----- ----
-3 -3


-3 crosses out so you are left with "y", and -12 divided by -3 and it will be 4, because if you divide a negative by a negative, you will get a positive. so substitute "y" with 4. choose any equation, i will pick "2x+1y=-6". 2x+1(4)=-6, multiply 4, so it would look like this: 2x+4=-6. subtract 4 to the other side, so it would be -6-4, or -6+(-4), that would equal -10, then it would be 2x=-10, that would be x=-5, so your points would be (-5,4). This is how you check your answer: since your points are (-5,4), -5 is your "x", and your 4 is "y". choose any equation. i will pick 2x+1y=-6, substitute, 2(-5)+1(4)=-6, then you multiply. -10+4=-6. -10+4=-6, so it's -6=-6. so it's true, because, the solution is a number equals a number (10=10, -2=-2 and so on). Lets check the other equation just in case. 3(-5)+3(4)=-3, the equation would look like this: -15+12=-3, then add -15+12 and your answer is -3, and now it's -3=-3, since they are the solution, the answer is correct.

So the answer is (-5,4).

Answer 3

Start with the first one:
3x + 3y = -3
3y = -3 - 3x
Divide both sides by 3 to get
y = -1 -x

Now plug this into the second equation:
2x + 1y = -6
2x + 1(-1-x) = -6
2x + -1 + -x = -6
x + -1 = -6
x = -6 + 1
x = -5

Now go BACK to the first one, and insert -5 for x:
3x + 3y = -3
3 (-5) + 3y = -3
-15 + 3y = -3
3y = -3 + 15
3y = 12
y = 4

Good luck.

Answer 4

hokay! so first, you want to make sure both equations are equal the same one variable. let's make it y, here.

3x + 3y = -3
3x - 3x + 3y = -3 - 3x
3y = -3x - 3
y = -x -1

2x + y = -6
2x - 2x + y = -6 - 2x
y = -2x - 6

then it follows that:
y = -x -1 = -2x - 6
so:
-x - 1 = -2x - 6

solve for x:

-x + 2x -1 = -2x + 2x - 6
x - 1 = -6
x - 1 + 1 = -6 +1
x = -5

then go back to either one of your (y=) equations and replace x with its now-known value of -5 to get the value of y:

y = -x -1
y = -(-5) -1
y = 5 - 1
y = 4

So: x = -5 and y = 4

If you want to verify your answer, just plug in those values in the original equations:

3x+3y=-3
3*(-5) + 3*4 = ?
-15 + 12 = -3 so that's good
and
2x+y=-6
2(-5)+4=?
-10+4=-6 so that's good, too!

Answer 5

Multiply equation #1 by 2, giving: 6x+6y= -6

Multiply equation #2 by -3, giving: -6x-3y= 18

Add the two equations together, giving: 0x+3y=12, so y=4

Substitute this value for y into equation #1-- 3x+3(4)= -3, so x= -5.

Check your work by substituting both values just calculated for x and y (x=-5 and y=4) into your original equations. Should do it.

Good luck.

Answer 6

3x+3y=-3
2x+y=-6

divide first eq . by 3
x+y=-3
2x+y=-6

now multiply both with each others coefficient
so
2x+2y=-6 ------1
2x+y =-6------------2
subtract 2 from 1
y=0
put y =0 in 1
2x+0=-6
x=-3
y=0

Answer 7

x= -5, y=4

Answer 8

3x + 3y = -3 ........ divide by 3
x + y = -1

subtract from other equation:

2x + y = -6
x + y = -1
---------------
x ....... = -5

then plug it in:

2(-5) + y = -6
-10 + y = -6
y = 4

Answer 9

x=-5
y=4

It took me so much time ='(