Question

How do I use elimination for he equations 2x+10y=-20 and -x+4y=28?

Answer 1

Answer:

Using the elimination method to solve for x and y; ANSWER: y=2 & x=-20

Step-by-step explanation:

1) It helps to visualize the equation if you put the second equation underneath the first like regular adding.  

  (2x+10y= -20)

+ (-x+4y= 28)

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2) You always want to cancel out one value (x or y) to start the process.

In this case, if I can get a -2x to cancel out 2x (neg. and positive cancel), that would cancel out the x's in the two equation. To do that, I would multiply by 2 to the second equation and add like you would normally (like terms with like terms, x with x and y with y)

2x+10=-20   2(-x+4y=28) ---> 2x+10y= -20 plus -2x+8y=56 --->18y=36 (this is the final simplified outcome)

3) find y so y =36/18     so y =2

4) Plug y=2 back into one of the original equation and solve for x

2x+10(2)= -20 ---> x=-20