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解答下列各题:(1)分解因式:4a2-8ab+4b2-16c2(2)计算:(2a+b)(2a-b)+b(2a+b)-8a2b÷2b(3)化简求值:(3x+4x2-1-2x-1)÷x+2x2-2x+1,其中x=-3(4)解分式方程:xx-2-1=8x2-4.

题目详情
解答下列各题:
(1)分解因式:4a2-8ab+4b2-16c2
(2)计算:(2a+b)(2a-b)+b(2a+b)-8a2b÷2b
(3)化简求值:(
3x+4
x2-1
-
2
x-1
)÷
x+2
x2-2x+1
,其中x=-3
(4)解分式方程:
x
x-2
-1=
8
x2-4

222
2
3x+4
x2-1
-
2
x-1
)÷
x+2
x2-2x+1
,其中x=-3
(4)解分式方程:
x
x-2
-1=
8
x2-4
3x+4
x2-1
3x+4x2-13x+43x+4x2-1x2-1x2-1x2-12-1
2
x-1
)÷
x+2
x2-2x+1
,其中x=-3
(4)解分式方程:
x
x-2
-1=
8
x2-4
2
x-1
2x-122x-1x-1
x+2
x2-2x+1
,其中x=-3
(4)解分式方程:
x
x-2
-1=
8
x2-4
x+2
x2-2x+1
x+2x2-2x+1x+2x+2x2-2x+1x2-2x+1x2-2x+1x2-2x+12-2x+1
x
x-2
-1=
8
x2-4
x
x-2
xx-2xxx-2x-2
8
x2-4
8
x2-4
8x2-488x2-4x2-4x2-4x2-42-4
▼优质解答
答案和解析
(1)原式=4(a22-2ab+b22-4c22)
=4[(a22-2ab+b22)-4c22]=4[(a-b)22-4c22]
=4(a-b+2c)(a-b-2c);
(2)原式=4a44-b22+2ab+b22-4a22=2ab;
(3)原式=[
3x+4
(x+1)(x-1)
-
2
x-1
x+2
(x-1)2

=
3x+4
(x+1)(x-1)
(x-1)2
x+2
-
2
x-1
(x-1)2
x+2

=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
3x+4
(x+1)(x-1)
3x+4(x+1)(x-1)3x+43x+43x+4(x+1)(x-1)(x+1)(x-1)(x+1)(x-1)-
2
x-1
x+2
(x-1)2

=
3x+4
(x+1)(x-1)
(x-1)2
x+2
-
2
x-1
(x-1)2
x+2

=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
2
x-1
2x-1222x-1x-1x-1]÷
x+2
(x-1)2

=
3x+4
(x+1)(x-1)
(x-1)2
x+2
-
2
x-1
(x-1)2
x+2

=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
x+2
(x-1)2
x+2(x-1)2x+2x+2x+2(x-1)2(x-1)2(x-1)22
=
3x+4
(x+1)(x-1)
(x-1)2
x+2
-
2
x-1
(x-1)2
x+2

=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
3x+4
(x+1)(x-1)
3x+4(x+1)(x-1)3x+43x+43x+4(x+1)(x-1)(x+1)(x-1)(x+1)(x-1)•
(x-1)2
x+2
-
2
x-1
(x-1)2
x+2

=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
(x-1)2
x+2
(x-1)2x+2(x-1)2(x-1)2(x-1)22x+2x+2x+2-
2
x-1
(x-1)2
x+2

=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
2
x-1
2x-1222x-1x-1x-1•
(x-1)2
x+2

=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
(x-1)2
x+2
(x-1)2x+2(x-1)2(x-1)2(x-1)22x+2x+2x+2
=
(3x+4)(x-1)
(x-1)(x+2)
-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
(3x+4)(x-1)
(x-1)(x+2)
(3x+4)(x-1)(x-1)(x+2)(3x+4)(x-1)(3x+4)(x-1)(3x+4)(x-1)(x-1)(x+2)(x-1)(x+2)(x-1)(x+2)-
2(x-1)2
(x-1)(x+2)

=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
2(x-1)2
(x-1)(x+2)
2(x-1)2(x-1)(x+2)2(x-1)22(x-1)22(x-1)22(x-1)(x+2)(x-1)(x+2)(x-1)(x+2)
=
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)

=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
(3x+4)(x-1)-2(x-1)2
(x-1)(x+2)
(3x+4)(x-1)-2(x-1)2(x-1)(x+2)(3x+4)(x-1)-2(x-1)2(3x+4)(x-1)-2(x-1)2(3x+4)(x-1)-2(x-1)22(x-1)(x+2)(x-1)(x+2)(x-1)(x+2)
=
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)

=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
(x-1)[(3x+4)-2(x-1)]
(x-1)(x+2)
(x-1)[(3x+4)-2(x-1)](x-1)(x+2)(x-1)[(3x+4)-2(x-1)](x-1)[(3x+4)-2(x-1)](x-1)[(3x+4)-2(x-1)](x-1)(x+2)(x-1)(x+2)(x-1)(x+2)
=
3x+4-2(x-1)
x+2

=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
3x+4-2(x-1)
x+2
3x+4-2(x-1)x+23x+4-2(x-1)3x+4-2(x-1)3x+4-2(x-1)x+2x+2x+2
=
x+2
x+2

=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x2-4)=8,
去括号,得x2+2x-x2-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.
x+2
x+2
x+2x+2x+2x+2x+2x+2x+2x+2
=1;
(4)方程两边同时乘以(x+2)(x-2)得,x(x+2)-(x22-4)=8,
去括号,得x22+2x-x22-4=8,
解得:x=6,
检验:当x=6时,(x+2)(x-2)=8×4=32≠0.
则x=6是方程的解.