o.28x8.6+7.2xo.86
=o.28x8.6+0.72x8.6
=(o.28+0.72)x8.6
=1x8.6
=8.6
o.28x8.6+7.2xo.86
=2.8×0.86+7.2×0.86
=0.86×(2.8+7.2)
=0.86×10
=8.6
0.28×8.6+7.2×0.86
=2.8×0.86+7.2×0.86
=0.86×(2.8+7.2)
=0.86×10=8.6
o.28x8.6+7.2xo.86
=o.28x8.6+0.72x8.6
=(0.28+0.72)x8.6
=1x8.6
=8.6