10x-3.14*x*x*0.25=3.14*x*x*0.75 10x=3.14*x*x*0.75 +3.14*x*x*0.253.14*x*x*(0.75 +0.25)-10x=03.14*x*x-10x=0x(3.14x-10)=0x1=0,3.14x-10=0,x2=10/3.14=100/314=50/157≈3.185,