Question

Solve the following system by using graph paper or graphing technology.

2x + 2y = –6
3x – 2y = 11

What is the solution to the system?

Answer 1

Answer possibilities are:
(2, –1)
(1, –4)
(3, –2)
(–1, –7)
Last time I tried to solve it, I got 2, -1, and it was marked incorrect. But that's always the answer I get. :/ So.. I must be doing something wrong. x.x Help, please? :o

Answer 2

Use a graphing calculator to get what you see attached


You'll see that the two lines intersect at the point (1,-4)


So the answer is choice B

Answer 3

Oh I should point out that the green line is 2x + 2y = –6 and the blue line is 3x – 2y = 11

Answer 4

Ohh. I know it said to solve by graphing, but I tried to solve by substitution instead. :/ But thank you. :D

Answer 5

If you want to use substitution, then...


Solve the first equation for y

2x + 2y = –6

2y = –6 - 2x

y = -6/2 - 2x/2

y = -3 - x

--------------------------

Then plug this into the second equation

3x – 2y = 11

3x – 2(-3 - x) = 11

3x + 6 + 2x = 11

5x + 6 = 11

5x = 11 - 6

5x = 5

x = 5/5

x = 1 <---- First part of the answer

---------------------------------

Now use this to find y

y = -3 - x

y = -3 - 1

y = -4 <---- Second part of the answer


So the solutions are x = 1 and y = -4 giving us the ordered pair (1, -4)

Answer 6

OH I meant to say elimination o.o

Answer 7

Either way, I probably did it wrong. xD But thank you very much. n.n

Answer 8

Add the two equations

2x + 2y = –6
3x – 2y = 11
------------
5x + 0y = 5

which gives us 5x = 5

Solve for x to get x = 1

Then use this to find y

3x – 2y = 11

3(1) – 2y = 11

3 - 2y = 11

-2y = 11 - 3

-2y = 8

y = 8/(-2)

y = -4

So we get the same answer

Answer 9

Oh, I see what I did wrong now. xD

Answer 10

that's great :)

Answer 11

can you break it down ?