(1)
+2 3
÷(1-1 3
),4 5
=
+2 3
÷1 3
,1 5
=
+2 3
×5,1 3
=
+2 3
,5 3
=
;7 3
(2)0.5×25×1.25×64,
=0.5×25×1.25×8×4×2,
=(0.5×2)×(25×4)×(1.25×8),
=1×100×10,
=1000;
(3)0.7×24.5+0.7×76.5-70%,
=0.7×24.5+0.7×76.5-0.7,
=(24.5+76.5-1)×0.7,
=100×0.7,
=70.