早教吧 育儿知识 作业答案 考试题库 百科 知识分享

①若mn=53,则m2+2mn+n2m2−mn−2n2=.②若x3=y4=z5,则x2−3xy+2z23x2+2xy−z2=−526−526.③已知1a+1b=4,则4a+3ab+4b−3a+2ab−3b=−1910−1910.④若m+n=5,mn=3,则nm+mn=193193.

题目详情
①若
m
n
=
5
3
,则
m2+2mn+n2
m2−mn−2n2
=______.
②若
x
3
=
y
4
=
z
5
,则
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
m
n
=
5
3
,则
m2+2mn+n2
m2−mn−2n2
=______.
②若
x
3
=
y
4
=
z
5
,则
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
m
n
mmnn
5
3
,则
m2+2mn+n2
m2−mn−2n2
=______.
②若
x
3
=
y
4
=
z
5
,则
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
5
3
5533
m2+2mn+n2
m2−mn−2n2
=______.
②若
x
3
=
y
4
=
z
5
,则
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
m2+2mn+n2
m2−mn−2n2
m2+2mn+n2m2+2mn+n2m2+2mn+n2m2+2mn+n22+2mn+n2n2n22m2−mn−2n2m2−mn−2n2m2−mn−2n2m2−mn−2n22−mn−2n2n2n22
x
3
=
y
4
=
z
5
,则
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
x
3
xx33
y
4
=
z
5
,则
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
y
4
yy44
z
5
,则
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
z
5
zz55
x2−3xy+2z2
3x2+2xy−z2
=
5
26
5
26

③已知
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
x2−3xy+2z2
3x2+2xy−z2
x2−3xy+2z2x2−3xy+2z2x2−3xy+2z2x2−3xy+2z22−3xy+2z2z2z223x2+2xy−z23x2+2xy−z2x2+2xy−z2x2+2xy−z22+2xy−z2z2z22
5
26
5
26
5
26
552626
5
26
5
26
5
26
552626
1
a
+
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
1
a
11aa
1
b
=4,则
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
1
b
11bb
4a+3ab+4b
−3a+2ab−3b
=
19
10
19
10

④若m+n=5,mn=3,则
n
m
+
m
n
=
19
3
19
3
4a+3ab+4b
−3a+2ab−3b
4a+3ab+4b4a+3ab+4b−3a+2ab−3b−3a+2ab−3b
19
10
19
10
19
10
19191010
19
10
19
10
19
10
19191010
n
m
+
m
n
=
19
3
19
3
n
m
nnmm
m
n
=
19
3
19
3
m
n
mmnn
19
3
19
3
19
3
191933
19
3
19
3
19
3
191933
▼优质解答
答案和解析
①m2+2mn+n2m2−mn−2n2=(mn)2+2mn+1(mn)2−mn−2=(53)2+2×53+1(53)2−53−2=-8;②令x3=y4=z5=k,则x=3k,y=4k,z=5k,所以x2−3xy+2z23x2+2xy−z2=(3k)2−3×3k×4k+2×(5k)23×(3k)2+2×3x×4k−(5k)2=−5k...