Alg. 2 question?? 10 points for best answer :)?

Question

Solve each system of equations using the elimination method.

4x+17y= -151

x-3y= 71

okay can you give me an explanation on how you found the answer and what method did you use? I don't even know what this is or where to start so any help would be nice thanks!

Answer 1

To use the elimination method, multiply one or both equations by something so when you add the two together, you eliminate either the x or the y.

The first equation has 4x.  Multiply every term in the second equation by -4 so the x's will be eliminated when you add the two equations together

4x+17y=-151

-4x+12y=-284

___________

      29y=435

Divide both sides by 29:

y=15

Now, plug in 15 for y and find x:

x-3*(15)=71

x-45=71

x=116

_/

Answer 2

multiply the entire bottom equation by 4 for the 4x on top and the -4x on bottom cancel out. then combine the rest and get 29y=435.  do your basic algerbra from there and get y=15.

no plug the 15 in for y in one of the equations and you will get x=116.

hope this helps!

Answer 3

"add down"...but multiply the 2nd equation by -4 in order to create a cancellation:   -4(x + -3y = 71) =  -4x + 12y = -284

4x     +      17y     =     -151

-4x     +     12y       =   -284

_________________________

               29y        =   -435

solve for y:   y = -435/29 = -15 then plug in this value in either ORIGINAL equation to find the x value.

x + -3(-15) = 71

x + 45 = 71

x + 45 + -45 = 71 + -45

x = 26   so the point is :  (26, -15)

Answer 4

The elimination method is used to remove one of the variables in a two equation system and solve for the remaining variable and then plug your answer back into either equation to determine the value of the remaining variable.  There are several ways to solve this, but one simple way is as follows:

4x + 17y = -151

(x - 3y = 71) * -4

4x + 17y = -151

-4x + 12y = -284

Add the like terms results in:

0x + 29y = -435

29y = -435

y = -15

Now substitute into either equation to find x:

4x + 17(-15) = -151

4x - 255 = -151

4x = 104

x = 26

Hope that helps!