35(1+x)^2+1.75(1+x)-48.3=0 (1+x)^2+(1+x)/20=48.3/35=6.9/5=1.38 (1+x)^2+(1+x)/20=1.38 (1+x+1/40)^2=1.38+1/1600 (x+1.025)^2=1.380625 x+1.025=±1.175 x1=0.15 x2=-2.2
