①(
-2 3
×3 4
)÷2 5
×6,1 6
=(
-2 3
)÷3 10
×6,1 6
=
×6×6,11 30
=
×6,11 5
=
;66 5
②99÷13×26÷33,
=(99÷33)×(26÷13),
=3×2,
=6;
③6.25×5.7-1.6×6.25+5.9×6.25,
=6.25×(5.7-1.6+5.9),
=6.25×10,
=62.5;
④(
+3 4
)+(12 25
-3 4
)-(8 21
+12 25
),13 21
=
+3 4
+12 25
-3 4
-8 21
-12 25
,13 21
=(
+3 4
)+(3 4
-12 25
)-(12 25
+8 21
),13 21
=
+0-1,3 2
=