(1.8-1.8x\1.2)-(1.3-1.3x\2)-(5x-0.4\0.3)=0(1.8-3x\2)-(1.3-1.3x\2)-(5x-4\3)=01.8-3x\2-1.3+1.3x\2-5x+4\3=0-3x\2+1.3x\2-10x/2+1.8-1.3+4/3=0-11.7x/2+11/6=0117x/20=11/6x=(11/6)*(20/117)x=110/351
(OA+OB)^2=12OC+1,