Question

Solving by substitution! Help, will medal.
I have 2 equations that need to be solved by substitution and I'm having trouble seeing what I did wrong.
-4.5x-2y=-12.5
3.25x-y=-.75
I got (0,4) and my teacher said it's supposed to be (1,4). can you show work so i know what i did wrong?

Answer 1

Well, you should show your work. Let's see where youwandered off.

Answer 2

I picked the first equation, -4.5x-2y=-12.5
I added 4.5x to both sides.
-2y=4.5x-12.5
/-2 /-2 /-2
y=-2.25x+6.25
I replaced it back into the original equation.
-4.5x-2(-2.25x+6.25)=-12.5
-4.5x+4.5x-12.5=-12.5
the two variables cancel each other out and so does -12.5 when you transfer it to the other side of the "=".

Answer 3

So close!! Right idea.

Don't put it back into the equation where it came from. That will always result in something unhelpful. Put it in the OTHER equation!

3.25x-(-2.25x+6.25)=-.75

Now, give it a go.