YolieBear
Answered

Westonci.ca is the trusted Q&A platform where you can get reliable answers from a community of knowledgeable contributors. Get detailed and accurate answers to your questions from a community of experts on our comprehensive Q&A platform. Join our platform to connect with experts ready to provide precise answers to your questions in different areas.

how do you solve 3x-2y=-5 ; 3y-4x=8 for x and y. Explain please.

Sagot :

3x-2y=-5
3y-4x=8

1) multiply the first equation by 3
   3(3x-2y=-5)   this will give you the new equation: 9x-6y=-15

2) multiply the second equation by 2
   2(3y-4x=8)    this should give you the equation: 6y-8x=16

3) combine both equations/ like terms
    9x-6y=-15
    6y-8x=16

4) -6y and 6y cancel out 
    9x=-15
    -8x=16

5)  9x and -8x combine to make 1x or just x and -15 combined with 16 gives you just 1

6) we are now left with:
    x=1 

7) plug in the x to any of the two original equations ( i chose the first) 
   3x-2y=-5 
   3(1) - 2y = -5
   3 - 2y = -5
   -2y = -8
   y = 4
   When you plug in the x=1 you are given 3(1) - 2y = -5
   Distribute the 3 and you should have 3 - 2y = -5
   Subtract 3 from 3 (this cancels out) then from -5
   This should leave you with -2y = -8 ( -3 and -5 add to -8)
   Divide by -2 ( -2 divided by -2 cancels out) 
   -8 divided by -2 gives you 4 (two negatives make a positive)
   
So, y=4 and x=1
 To check, plug in x=1 and y=4 into one equation. when you're done with that you can plug them into the other. when you plug them into the first equation you get -5=-5 which means they worked. when plugged into the second, the result is 8=8 which means x=1 and y=4 worked for both equations. 

   

Thanks for stopping by. We are committed to providing the best answers for all your questions. See you again soon. We appreciate your time. Please come back anytime for the latest information and answers to your questions. Get the answers you need at Westonci.ca. Stay informed with our latest expert advice.