i dont get it. i can solve them with the elimination method fucking easily, but by substitution i get the wrong answer every fucking time. why?? why does my brain go vegetable when i do this??
>>8054708
I will help you if you rewrite it with proper x's.
it's because of your bad handwriting so you can't tell if line 2 starts with a one or a seven
What do you mean by substitution? Solving one for a variable and then putting that variable into the other equation (not native english...)
Could you post your entire thought process? That will make it more easy to help you.
>>8054740
You're probably just being messy with your parentheses.
I would guess that when you divide, you forget to divide the entire side of the equation.
Then when you've solved for x and plug it into the other equation you need to put parenthesis around it.
Solve them with a matrix instead of with shitty 10th grade math.
>>8054798
>implying solving a system of linear equations is not the exact same thing
>>8054708
Because you're going it wrong.
>>8054819
Doing** sorry
>>8054708
Well, two non-parallel straight lines meet at one and only one point. Can't help it if you're a retard.
>>8054708
It works both ways, obviously.
Move to /wsr/
>>8054708
>I'm 12 and what are matrices?
From the first eq
4x+y=23
y=23-4x
Now you can work on the second eq
7x+3(23-4x)=47
7x+69-12x=47
-5x=-22
x=22/54=4.4
y=5.4
