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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:(
-
)÷
,其中x=-3
(4)解分式方程:
-1=
.
222
2
-
)÷
,其中x=-3
(4)解分式方程:
-1=
.
3x+4 x2-1 3x+4 3x+4 x2-1 x2-1 x2-1x2-12-1
)÷
,其中x=-3
(4)解分式方程:
-1=
.
2 x-1 2 2 x-1 x-1
,其中x=-3
(4)解分式方程:
-1=
.
x+2 x2-2x+1 x+2 x+2 x2-2x+1 x2-2x+1 x2-2x+1x2-2x+12-2x+1
-1=
.
x x-2 x x x-2 x-2
.
8 x2-4 8 8 x2-4 x2-4 x2-4x2-42-4
(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 |
(4)解分式方程:
x |
x-2 |
8 |
x2-4 |
222
2
3x+4 |
x2-1 |
2 |
x-1 |
x+2 |
x2-2x+1 |
(4)解分式方程:
x |
x-2 |
8 |
x2-4 |
3x+4 |
x2-1 |
2 |
x-1 |
x+2 |
x2-2x+1 |
(4)解分式方程:
x |
x-2 |
8 |
x2-4 |
2 |
x-1 |
x+2 |
x2-2x+1 |
(4)解分式方程:
x |
x-2 |
8 |
x2-4 |
x+2 |
x2-2x+1 |
x |
x-2 |
8 |
x2-4 |
x |
x-2 |
8 |
x2-4 |
8 |
x2-4 |
▼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=[
-
]÷
=
•
-
•
=
-
=
=
=
=
=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 3x+4 3x+4(x+1)(x-1) (x+1)(x-1) (x+1)(x-1)-
]÷
=
•
-
•
=
-
=
=
=
=
=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 2 2x-1 x-1 x-1]÷
=
•
-
•
=
-
=
=
=
=
=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+2 x+2(x-1)2 (x-1)2 (x-1)22
=
•
-
•
=
-
=
=
=
=
=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 3x+4 3x+4(x+1)(x-1) (x+1)(x-1) (x+1)(x-1)•
-
•
=
-
=
=
=
=
=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)2 (x-1)2 (x-1)22x+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 2 2x-1 x-1 x-1•
=
-
=
=
=
=
=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)2 (x-1)2 (x-1)22x+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) (3x+4)(x-1) (3x+4)(x-1)(x-1)(x+2) (x-1)(x+2) (x-1)(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 2(x-1)2 2(x-1)22(x-1)(x+2) (x-1)(x+2) (x-1)(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 (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)
=
=
=
=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)[(3x+4)-2(x-1)] (x-1)[(3x+4)-2(x-1)](x-1)(x+2) (x-1)(x+2) (x-1)(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) 3x+4-2(x-1) 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+2 x+2 x+2 x+2x+2 x+2 x+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.
=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) |
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 |
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 |
=
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) |
(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 |
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 |
(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 |
=
(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) |
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) |
=
(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) |
=
(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) |
=
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 |
=
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 |
=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.
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七年级数学试卷二元一次方程组单元测试要答案问题给了1、若xa-b-2ya+b-2=11是二元一次方程 2021-01-22 …
一元一次方程3.解方程2分之x-6分之x-2=1,去分母正确的是a.3x-x+2=1b.3x-x-2 2021-01-28 …