(1)
×58+42÷8,1 8
=
×58+42×1 8
,1 8
=(58+42)×
,1 8
=100×
,1 8
=12.5;
(2)
×99+4 25
,4 25
=
×99+4 25
×1,4 25
=
×(99+1),4 25
=
×100,4 25
=16;
(3)48×(
+1 2
+1 3
),1 4
=48×
+48×1 2
+48×1 3
,1 4
=24+16+12,
=52;
(4)
+3 8
×0.35+0.65÷15 4
,4 15
=
+3 8
×0.35+0.65×15 4
,15 4
=
+(0.35+0.65)×3 8
,15 4
=
+1×3 8
,15 4
=
+3 8
,15 4
=
33