Answered

Westonci.ca is the ultimate Q&A platform, offering detailed and reliable answers from a knowledgeable community. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields. Our platform offers a seamless experience for finding reliable answers from a network of knowledgeable professionals.

4x + 12 = -7y
-y + 12 = 4x
Solve with elimination

Sagot :

Take the second equation and flip it around so the y on the left ends up on the right and the 4x on the right ends up on the left.  This makes all negatives positive and all positives negative.   -4x   + 12  = y 

Then add the first equation to the second equation 
4x   +12   = -7y
-4x   + 12  = y    this eliminates the x's
          24 = - 6y            then divide by - 6
           - 6     - 6
         - 4    = y

So if you know that y = negative 4, you can substitute into either equation.  I pick the second one because I am a lazy person.  
  -y  + 12  = 4 x
-(-4) + 12 = 4 x     combine your numbers
     16      = 4 x        then divide by 4
       4      =  x
So your solution is: x = 4 and y = -4 or this is also written (4, -4)

Does that work for you?
Lilith
[tex]\begin{cases}4x + 12 = -7y \\ -y + 12 = 4x \end{cases} \\ \\\begin{cases}4x + 7y = -12 \\ -4x-y =-12 \end{cases} \\+ ------- \\6y=-24\ \ /:6\\ \\y=-\frac{24}{6}\\ \\y=-4[/tex]

[tex]4x+12=-7y\\ \\ 4x+12=-7*(-4)\\ \\4x=28-12\\ \\4x=16\ \ /:4\\ \\x=\frac{16}{4}\\ \\ x=4 \\ \\ \begin{cases}x=4 \\ y=-4 \end{cases}[/tex]


Thanks for using our platform. We aim to provide accurate and up-to-date answers to all your queries. Come back soon. Thank you for your visit. We're committed to providing you with the best information available. Return anytime for more. Stay curious and keep coming back to Westonci.ca for answers to all your burning questions.