How do you solve the following system?: -2x +5y =-6 , 3x +2y = -1

1 Answer
EZ as pi
Aug 15, 2016

x = 7/19 and y = -20/19

Explanation:

As the x-terms have different signs, we will eliminate them by using an LCM of 6 and adding.

-2x +5y =-6.............................................. A

3x +2y = -1....................................................B

Ax3: -6x+15y = -18.......... ......................................C

Bx2: " "6x+4y=-2........................................................D

C+D:" " 19y= -20

y = (-20)/19

Substitute (-20)/19 for y in B

3x + 2((-20)/19) = -1 " "xx19

19xx3x + (-40)/19xx19 = -1xx19

57x-40 = -19

57x = 21

x = 21/57 = 7/19

Check in A

(-2xx7)/19 +(5xx(-20))/19

(-14-100)/19

-114/19

=-6

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