How do you solve the following system?: #-2x+10y=-20 , 2x+3y=11 #

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Answer 1 · 2016-01-21T09:15:27

#{ (x=(85)/13),(y=-9/13) :}#

#{ (-2x+10y=-20" S1"),(2x+3y=11" S2") :}#

You can use Linear Systems with Addition or Subtraction doing #S1+S2# to remove #x# (in the equations #x# has same coefficent and opposite sign).

You also could divide the first equation #S1# by #2#

#{ (-cancel(2)x+cancel(10)^5y=-cancel(20)^10" S1/2"),(0x+13y=-9 " S1+S2") :}#

#=>{ (-x+5y=-10),(y=-9/13) :}#

#{ (-x=-10-5*(-9/13)),(y=-9/13) :}#

#{ (x=10-45/13),(y=-9/13) :}#

#{ (x=(130-45)/13),(y=-9/13) :} =>{ (x=(85)/13),(y=-9/13) :}#

graph{(10y-2x+20)(3y+2x-11)=0 [3.734, 8.059, -1.165, 0.998]}