1.25 x3.6+ 12.5x0.64=1.25 x3.6+1.25×6.4=1.25 x(3.6+6.4)=12.5
1.25 x3.6+ 12.5x0.64=1.25 x3.6+ 1.25x6.4=1.25 x(3.6+6.4)=1.25x10=12.5
1.25x3.6+12.5x0.64=12.5x0.36+12.5x0.64=12.5x(0.36+0.64)=12.5x1=12.5
12.5