湘教版七年级下数学教案(全册)

x+y=46.x+y=5.6(13x+12y=46.4,13%-12y=5.6)

x=1x=0x=0.1X=100

y=45.4y—46.4y=46.3y=-200

x+y=46.4

x=26\x-1x+y=46.4

y-20.4y-45.4x-y=5.6

x+y=46A(1)1+(1-5.6)=46.4与1+,=46.4

x+(x-5.6)=46.4

x-y—5.6(2)

x+y=46.4中的丁就是％-5.6y=x-5.6

5x-y=-9(1)

y=-3x+l(2)

'2x-3y=0(1)

<5x-7y=l⑵

y=—3x+l

'2x+5y=9(1)

’2x-3y=17⑵

-0.5x+y=46x+3y=9

0.5%+3y=87x+3y=10

3m-n—6=03x-4y=10

4/TI-n-4=03x=2y+4

7x+3y=1

<2x-3y=8

2x-3y=9

3x=3y-l1

m-n=5

3m-n=-1

|2x+3y+5|+(5x-3y+2)2=0

‘5x-4y=18

5x+4y=2

2x+3y=-11

6x-5y=9

3x+4y=8

4x+3y=-1

5x-3y=13

2%+4y=0

3x3a+A+4y2a-/)=4

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4x-3y=93x+y=9

y=x+l-2x-y=-6

6x+y=72x+5y=12

3x=y+23x+2y=7

2x+y=12x+y=1，6x+3y=3

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2x+y=—24x+2y=-4[4x+2y=-4

2x+y=1x-3y=10

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4x+2y=2[-2x+6y=-20

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(a)-a=一(疗)3.(/〃2六=(X)=

(a5)3=a8a2-a3-abx2+%3=x5x2-x2-x4

23x53=x==(___x_彳

28X58=x==(_x_J

2,2X5,2=x==(_x_严

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3。+2x^(-b)+y•3。+y•(-b)

6ax—2bx+3ay-by

(2x+y)(x-3y)

(2a+0)2

(2x+y)(x-3y)

2x2-6xy+xy-3y2

2x2-5xy-3y2

(2〃+〃)2

(2a+b)(2a+b)

4a2+2ab+2ba+b2

4a2+4"+〃

IDn

(x+3)(x-4)

-4x+3x—12

—x—12

(x+a)(x+Z?)

x1+bx+ax+abX

x2+(tz+b)x+ab

(a+b)(a-b)

(a+〃)2

(a-b)2

(%+2)(%-2)(1+3Q)(1-3Q)(a4-b^a-b)

(〃+。，。一/?)=a?-b2

(2x+1)(2x-1)(x+2yXx-2)，)

(2x)2-l2x2-(2y)2

4x2-1x2-4y2

(-2x-gy)(-2x+g,)(-4Q—b)(-4Q+Z?)

(-2x--y)(-2x+^-y)(-2x)2y)24x2-^-y2

(2x+y)2

(〃+加2=〃2+2加〃2

(a+bl2=a?+2，a-Z7+Z?2

(2x+y)2=(2x)2+2•(2x)•y+y?

(2x—y)2=(2x)2+2•(2x)•(—y)+(—y)2

=4x2—4xy+y2

(a+b)2=a2+2ab+b?(a-b)?=a2-2ab+b2

(a±h)2=/±2ahS

(3a+0)2(x--)2

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(-x+1)~(—2x—3)~

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(a+h\a-b)=a2-b2

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(a-b)2(b-a)2

(a+/?)2(-a-b)2

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1002+2X100X4+42

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(a+b+c)〜(2x—3y+z)~

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[a^b^a-b)=a2-b2

(Q+Z?)〜=a"+2QZ?+Z?〜

(。一。)2=a2-2ab-vb2

(Q+0+C)2a2+b2+c2+2ab+2ac+2bc

(-ci-h^ci—hj(-a-b^ci+b)

(x+lXx2+l)(x-l)

[a+Z7)2-(a-b)2(a+b)2+(a-Z?)2

(a+b)2_(a_b)2

[[a+力)+(Q—/?)][(a+h)-(a-b)]

(2a)•(2b)=2ab

(a+b)2+(a-b)2

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a~+2aZ?+/?~4-cr—2ab+b-

2a2+2h2

(%+y+l)(x+y—1)(a-b+1)(。+b—1)

(x+y+l)(x+y_l)

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[a-(b-\)][a+(b-l)]

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(ab)n=an・b〃

(x+a)(x+h)x2+hx+ax+abx2+(a+b)x-^-ab

(Q+〃)(Q_〃)=Q2

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(a±b)(a2+2ab+b2)=a3±Z?3

(tz±Z?)3=a3±3a2b+3ab2±b3

(a+b+c)2a2+b2+c2+2ah+2ac+2bc

4a2b-5h3+ab2+42a2b+3ab2-2+3ay

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-a•(-a)•(-a1•(一Q)4

(a+3)(。-3)—(a—l)(a+4)

(2Q+3)2-3(2a-l)(a+4)

(xy+1)2-(xy-1)2

(2a+3b丫-(2a-3b)(2a+3b)+(2a-3b)2

(a-h-3)(〃一〃+3)

(a+b—c)〜—(a—b+c)〜

(2x+y)(2x—y)(4f+)，2)

2(a+b)(a-b)-(a+b)2+(«+Z?)2M中a=2,b=—

2

(X+3)(J-3)-(X-1)(J+4)=X+3

哆丝

¥5：策3

1=0

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Sx2y4-\2xy2z

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(tz+c)(ci—b)~一(a—c)(〃-a)-

-I2xy2(x+y)+18，y(x+y)

(a+c)(a—b)~一(a—c)(b—a)一

-12xy2(x+y)+18x2y(^+y)

x2-25

⑴4，_y2

25x2-—y2

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(x+y)?-(x-y+1)2

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x-y

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