问题 解答题
计算:
(1)(
1
3
)
-3
+42+20120
(2)(
2
y3
-
3
y2
+
4
y
)•y6
(3)
(1+m)2
m
-
1+2m2
m
答案

(1)(

1
3
-3+42+20120

=27+16+1

=44;

(2)(

2
y3
-
3
y2
+
4
y
)•y6

=

2
y3
•y6-
3
y2
•y6+
4
y
•y6

=2y3-3y4+4y5

(3)

(1+m)2
m
-
1+2m2
m

=

1+2m+m2-1-2m2
m

=

2m-m2
m

=2-m.

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