Can anyone show me how to do solving systems by substitution?

its pretty simle if ur talking about what im thinking about… u have 2 equations (im making these up,this one will be easy)

y=8x+2 x+12+4y=8

so u plug watevr why equals (subsituting) into where the y is in the other equation and it the y= isnt already given to u, u have to solve one of the equations to make y= first… so then its

x+12+4(8x+2)=8

and then u solve first u distribute the 4

x+12+32x+8=8

and then combine like terms

33x+20=8

minus 20 from both sides 33x=-12

then divide by 33… well its not as easy as i thot but u get my poin and that woul dbe half ur answer and then u would plug tht number back in one of the originl equations and u have ur x,y answer i hoped i helped

well first u solve for x uz there is no y so it would b 2x=5-y and then u divide by 2 to get x alone and it would be x=5/2-y/2 which is hard to solve but then u would plug that into the x’s in the other equation and solve

ouu im doing tht too in school…

yeaa….. my biggest threat of passing this class going on to senior year is not happening in my condition:/ im flunking i wont be able to go on either unless i being my well…. 45 up….

seriusly im in gr.8 and im learning this!

yeaa….. my biggest threat of passing this class going on to senior year is not happening in my condition:/ im flunking i wont be able to go on either unless i being my well…. 45 up….

sorry if that repeated. well i have a learning disability

learning math ain’t so easy for me my class has me and my friend (2 juniors) at least 4(sophmores and the rest well (freshmen)

ahhh i see … wel the letters X or wte represents the # u dont kno and if the letter ( X) is beside a number tht means u mutilply it ( EX: 3x= 12) SO tht X would mean 3 x __ = 12 so 3 times what equals 12….. 4! so 3 x 4 =12!!

ohhhh okie dokie then;) thx a bunchI have trouble also paying attention:/

or a hard way… lets say this was ur math problem…… this is an easy way to solve….

2x-8 + 7x+ 2 …

u would put all letters on one side… so u would put the 7x on the left side

2x-7x ( but if u switch a # to another side u need to make it the opposite of wat it is so in this case it turns into -7x but there is already a - ( minice) soooo.. u dont need to change it…. ak so now u put the 7x into the 8’s spot so the 8 goes into the 7’s spot making it

2x-7x = -8+2 ( see how u switch the 8 and it became negative since u switch it…but if it was already negative u would make it positive .. meaning u would remove the - )

so now u have this

2x-7x = -8+2

so u solve the left side first.. ( 2x-7x )

so what 2-7..? its -5 so thts one ans… now the other side…..

-8+2 ..? its -6 so thts means ur ans issss…

-5-6 and whats -5-6 tht is -11

and thts ur ans !!! or if u just need to simplify it it woudl just be -5=-6

Hmmm…. okie dokie then… i think i got it now. Im not the smartest kid around or even smarter then the average bear could handle

Did you make these two equations up or did they give it to you in class?

Because the second equation -8x + 8x = 28 does not make sense i.e. it is not possible to solve, because

-8x + 8x = 28 ends up being 0 = 28 and 0 cannot be 28

I will be using different equations to explain it to you: First thing before you start a maths question remember your basic rules, which are:

For normal maths: ^ (squared) comes first THEN X and / THEN

• and - so if you do not know where to start, start with this

Secondly for equations: If a plus goes over the equal sign it becomes a minus and vice versa If something is multiplied on one side, you have to divide everything to get rid of it

Now let us start 1y +2x = 6 and 2x = 4 So start with the equation with only the one variable i.e. the second one and solve x 2x = 4 thus x = 2

Now substitute x into the other equation to get y

1y + 2(2) = 4 First do the X i.e. 1y + 4 = 4 Thus 1y = 0 Therefore y = 0/1 Therefore y = 0

find out what x is