[Help] help i can't do simultaneous equations? Updates to this post /post/218605-help-i-cant-do-simultaneous Tue, 08 Dec 2009 03:20:44 +0100 Reply from ɐʇɐɯɹǝɟ.Suc /post/218605-help-i-cant-do-simultaneous#reply-4501843 4x + y = 12
3y - y = 2

I would guess that is equivalent to
4x + y = 12
0x + 2y = 2

There
8x + 2y = 24
0x + 2y = 2

8x = 22
4x = 11
2x = 5.5
x = 2.75

11 + y = 12
y = 1

x = 2.75 and y = 1

]]> ɐʇɐɯɹǝɟ.Suc Mon, 17 Nov 2008 22:14:49 +0100 Reply from darkscorpia /post/218605-help-i-cant-do-simultaneous#reply-4501673 4x + y = 12
3x - y = 2

7x / = 14

x = 7
14

x = 2

Now pick an equation and put the answer instead of it.

Example: 4 (2) + y = 12.

8 + y = 12

y = 12 - 8

y = 4

Therefore x = 2 y = 4

]]> darkscorpia Mon, 17 Nov 2008 21:07:00 +0100 Reply from Anonymous /post/218605-help-i-cant-do-simultaneous#reply-4501333 need help i mean

]]> Anonymous Mon, 17 Nov 2008 19:18:41 +0100 Reply from Anonymous /post/218605-help-i-cant-do-simultaneous#reply-4501331 nice help plz!

]]> Anonymous Mon, 17 Nov 2008 19:18:24 +0100 Reply from Anonymous /post/218605-help-i-cant-do-simultaneous#reply-4501279 it ok but i don’t get it cause 3y and 4x are not the same so i dunno how to solve it out

]]> Anonymous Mon, 17 Nov 2008 19:05:19 +0100 Reply from Penguin B☺y Brian /post/218605-help-i-cant-do-simultaneous#reply-4501239 sorri

]]> Penguin B☺y Brian Mon, 17 Nov 2008 18:48:11 +0100 Reply from Anonymous /post/218605-help-i-cant-do-simultaneous#reply-4501229 it is 3y not 3x ok

]]> Anonymous Mon, 17 Nov 2008 18:44:15 +0100 The post was edited by don'tcare /post/218605-help-i-cant-do-simultaneous#reply-7300111 don'tcare Mon, 17 Nov 2008 18:43:40 +0100 The post was edited by Penguin B☺y Brian /post/218605-help-i-cant-do-simultaneous#reply-7300083 Penguin B☺y Brian Mon, 17 Nov 2008 18:39:43 +0100 Reply from Penguin B☺y Brian /post/218605-help-i-cant-do-simultaneous#reply-4501214 yea i kno, i realised that once i posted it.

]]> Penguin B☺y Brian Mon, 17 Nov 2008 18:38:44 +0100 Reply from ɐʇɐɯɹǝɟ.Suc /post/218605-help-i-cant-do-simultaneous#reply-4501190 Lol well it kinda messes up the whole thing if you make a mistake near the beginning

]]> ɐʇɐɯɹǝɟ.Suc Mon, 17 Nov 2008 18:32:33 +0100 Reply from Penguin B☺y Brian /post/218605-help-i-cant-do-simultaneous#reply-4501170 lol i kno i made a mistake i was just goin to fix it but guess u beat me to it

]]> Penguin B☺y Brian Mon, 17 Nov 2008 18:24:20 +0100 Reply from ɐʇɐɯɹǝɟ.Suc /post/218605-help-i-cant-do-simultaneous#reply-4501163 [quote Penguin Boy]easy… and that 3y has to be 3x or else its imposs
4x + y = 12
3x - y = 2 then times by 2

8x + 2y = 24
6x + 2y = 4 then cancel them down[/quote]

you did that right except the fact that they still arent the same because -y x 2 = -2y not +2y

]]> ɐʇɐɯɹǝɟ.Suc Mon, 17 Nov 2008 18:23:41 +0100 Reply from ɐʇɐɯɹǝɟ.Suc /post/218605-help-i-cant-do-simultaneous#reply-4501154 4x + y = 12
3x - y = 2

make them the same
12x + 3y = 36
12x - 4y = 8

subtract them
7y = 28
y = 4

sub y into equation
4x + 4 = 12
4x = 8

x = 2

therefore x = 2 and y = 4

]]> ɐʇɐɯɹǝɟ.Suc Mon, 17 Nov 2008 18:20:29 +0100 Reply from Anonymous /post/218605-help-i-cant-do-simultaneous#reply-4501148 thanx how did u get 40

]]> Anonymous Mon, 17 Nov 2008 18:18:46 +0100 Reply from Penguin B☺y Brian /post/218605-help-i-cant-do-simultaneous#reply-4501143 easy… and that 3y has to be 3x or else its imposs
4x + y = 12
3x - y = 2 then times by 2

8x + 2y = 24
6x + 2y = 4 then cancel them down

2x = 20 divide this by 2
x = 10

plug it in to equasion

40 + y = 12
so y = -28

]]> Penguin B☺y Brian Mon, 17 Nov 2008 18:17:18 +0100