simultaneous equations

[nike air max]

3. (2x + 3y = 19) (2x - 3y=22)
2.(3x - 4y = 13) (2x - 3y=20)
1.(3x + 2y = 12) (4x - y=5)
4. (5x - 2y = 14) (3x - y=9)
plese solve x and y

[Muffet]

3. Add the two together. Gives 4x = 41
so x = 10.25 and y = -0.5

2. Double the first and treble the second, and take one away from the other, giving y = -34 and x becomes -41

1. Double the second and add to the first, which gives
11x = 22. So x = 2 and y becomes 3

4. Double the second, and take one away from the other, whicxh gives x 4, and y becomes 3.

[Buzzie]

3. x = 10.25, y = -0.5
2. Can't get this one out, is there a typo in it??
1. x = 2, y = 3
4. x = 4, y = 3

[gen2]

I am not prepared to do your homework for you but I will show you how to do them.

If your two equations are:
3x - y = 9
4x +2y = 2

You first have to make either the number of Xs or the number of Ys the same in both equations by multiplying one or both of them by a suitable number.

In this case you could make the Ys equal by multiplying the first equation by 4 and the second equation by 3. It is in fact easier to make the Ys equal because you only have to multiply the first one by 2. The equations will now be:

6x - 2y = 18
4x + 2y = 2

You now want to get these Ys to cancel each other out. If they both had the same operator sign then you would subtract the equations. Here the signs are opposite, so you add them, giving you:

10x = 20
so x = 2

Now plug that back into one of the equations to get Y. Use the simplest one - in this case the first one.

6 - y = 9
so y = 6 - 9
so y = -3

Now it is your turn.

[porilo]

I love these and think I can still remember how to do them, even after not having studied maths for around 25 years! These are my answers, which I hope are correct:

3. x = 10.25, y = -0.5
2. x = -41, y = -34
1. x = 2, y = -3
4. x = 4, y = 3