Addition Method, please help.

Question

anonymous · Answer

1.  
To solve this system using the addition method, you would need to multiply the first equation by what number in order for the x's to add out? 2x + 3y = 8 -6x + 4y = 11  (2 points)

    3
    -3
    6
    None of the above

2.  
To solve this system using the addition method, you would need to multiply the first equation by what number in order for the y's to add out? 3x - y = 3 -2x + 2y = 6  (2 points)

    3
    2
    6
    None of the above

anonymous · Answer

? adition method for what

anonymous · Answer

k

anonymous · Answer

I think Problem 1 should look like:
   2x + 3y = 8
 -6x + 4y = 11

And problem 2 should look like:
    3x - y = 3
 -2x + 2y = 6

anonymous · Answer

So, for example, if you multiply the first equation in Problem 1 by 3, then the x term goes from being "2x" to become "6x"... then when you add the two equations, "6x" and "-6x" add and the x terms drop out.

anonymous · Answer

Problem 2 is the same idea...

anonymous · Answer

Solve the system using the addition method.

3x + 4y = -10
5x - 2y = 18

I think its none of the above

anonymous · Answer

the answers givin are 2, -2 , -4

anonymous · Answer

@JakeV8

anonymous · Answer

This is a new problem, right?

anonymous · Answer

yes

anonymous · Answer

Are you supposed to actually solve, or are you just supposed to tell what number to multiply one equation by to allow solving by the addition method?

anonymous · Answer

solve; and we didnt go over this at all.

anonymous · Answer

I noticed that if you multiply the 2nd equation by 2, you get a "-4y" term... then when you add the two equations, the -4y and 4y add to zero and drop out.

anonymous · Answer

okay i see that now.

anonymous · Answer

This is really confusing though... don't want you to get the wrong answer from a miscommunication here.

When you are asked to solve a system like this, if you can solve it, you end up with two numbers... the values of x and y.

If you actually solve that system we're looking at, you get x = 2, y = -4.  That happens to be two of the three numbers you listed as answers.

However, that's different than what you did on problem 1 and 2 earlier.  Those problems just wanted you to tell how you would START to solve by addition, not to actually solve.