Question 700254
20x+3y=20 and -20x+5y=60 using elimination 

20x+3y=20         -20x+5(10)=60
-20x+5y=60        -20x+50= 60     
-----------          -20x=  -50 +60
0+8y=80               --- ---
  -- --               -20x= 10
  8  8                ---- ---
y=10                    x=-0.5