a) (3-4x)^2 = 16(x-3)^2
b) (x^2+x+1)^2 =(4x-1)^2
1.16x^3y + 0,25yz^3
2.x ^4 – 4x^3 + 4x^2
3.2ab^2 – a^2b – b^3
4.a^3 + a^2b – ab^2 – b^3
5.x^3 + x^2 – 4x - 4
6.x ^3 – x^2 – x + 1
7.x ^4 + x^3 + x^2 – 1
8.x ^2y^2 + 1 – x^2 – y^2
9.x^4 – x^2 + 2x – 1
10.3a – 3b + a^2 – 2ab + b^2
có nhìn thấy j đâu ri msk
Phân tích các đa thức sau thành nhân tử.
1) a^2+ab+2b-4 2) x^3-x 3) x^2-6x+8 4) ab+b^2-3a-3b 5) x^3-4x^2-8x+8
6)9x^2+6x-8 7)x^2-y^2-4x+4 8)5x^3-10x^2+5x 9) 3x^2-8x+4 10) 4x^2-4x-3
11) x^2-7x+12 12)x^2-5x-14 13) 3x^2-7x+2 14) a.(x^2+1)-x.(a^2-1) 15) x^4+4
16) (x+2).(x+3).(x+4).(x+5)-24 17) (a+1).(a+3).(a+5).(a+7)+15
rút gọn biểu thức
a)A= (2x - 3)^2 - (2x + 3)^2
b)B= (x +1)^2 -2 (2x-1) (1+ x) +4x^2 - 4x + 1
`@` `\text {Ans}`
`\downarrow`
`A= (2x - 3)^2 - (2x + 3)^2`
`= [(2x - 3) - (2x + 3)]*[(2x - 3) + (2x + 3)]`
`= (2x - 3 - 2x - 3) * (2x - 3 + 2x + 3)`
`= -6 * 4x`
`= -24x`
`A=(2x-3)^2-(2x+3)^2`
`A=(2x-3-2x-3)(2x-3+2x+3)`
`A=-6.4x=-24x`
b: B=(x+1)^2-2(2x-1)(x+1)+4x^2-4x+1
=(x+1)^2-2(2x-1)(x+1)+(2x-1)^2
=(x+1-2x+1)^2
=(-x+2)^2=x^2-4x+4
1, (a - b)^2 (2a - 3b) - (b - a)^2 (3a - 5b) + (a + b)^2 (a - 2b)
2, x^4 - 4(x^2 + 5) - 25
3, (2 - x)^2 + (x - 2)(x + 3) - (4x^2 - 1)
4, (4x^2 - y^2) - 8(x - ay) - 4(4a^ - 1)
5, 16(xy + 6)^2 - (4x^2 + y^2 - 25)^2
6, (x + y - 2z)^2 + (x + y + 2z)^2 - 16z^2
7,(ax + 3y)^2 - (1 - 6a)(x^2 + y^2) + (3x - ay)^2
dài quá, làm từ từ nhé
1, \(\left(a-b\right)^2\left(2a-3b\right)-\left(b-a\right)^2\left(3a-5b\right)+\left(a+b\right)^2\left(a-2b\right)\)
\(=\left(a-b\right)^2\left(2a-3b-3a+5b\right)+\left(a+b\right)^2\left(a-2b\right)\)
\(=\left(a-b\right)^2\left(-a+2b\right)+\left(a+b\right)^2\left(a-2b\right)\)
\(=-\left(a-b\right)^2\left(a-2b\right)+\left(a+b\right)^2\left(a-2b\right)\)
\(=\left(a-2b\right)\left[\left(a+b\right)^2-\left(a-b\right)^2\right]\)
\(=\left(a-2b\right)\left(a+b-a+b\right)\left(a+b+a-b\right)\)
\(=4ab\left(a-2b\right)\)
2, \(x^4-4\left(x^2+5\right)-25=\left(x^2-25\right)-4\left(x^2+5\right)=\left(x^2-5\right)\left(x^2+5\right)-4\left(x^2+5\right)\)
\(=\left(x^2-9\right)\left(x^2+5\right)=\left(x-3\right)\left(x+3\right)\left(x^2+5\right)\)
3,\(\left(2-x\right)^2+\left(x-2\right)\left(x+3\right)-\left(4x^2-1\right)=\left(x-2\right)^2+\left(x-2\right)\left(x+3\right)-\left(4x^2-1\right)\)
\(=\left(x-2\right)\left(x-2+x+3\right)-\left(2x-1\right)\left(2x+1\right)\)
\(=\left(x-2\right)\left(2x+1\right)-\left(2x-1\right)\left(2x+1\right)\)
\(=\left(x-2-2x+1\right)\left(2x+1\right)\)
\(=\left(-x-1\right)\left(2x+1\right)\)
4, câu này đề thiếu
5,\(16\left(xy+6\right)^2-\left(4x^2+y^2-25\right)^2=\left(4xy+24\right)^2-\left(4x^2+y^2-25\right)^2\)
\(=\left(4xy+24-4x^2-y^2+25\right)\left(4xy+24+4x^2+y^2-25\right)\)
\(=\left[49-\left(4x^2-4xy+y^2\right)\right]\left[\left(4x^2+4xy+y^2\right)-1\right]\)
\(=\left[49-\left(2x-y\right)^2\right]\left[\left(2x+y\right)^2-1\right]\)
\(=\left(7-2x+y\right)\left(7+2x-y\right)\left(2x+y-1\right)\left(2x+y+1\right)\)
6, \(\left(x+y-2z\right)^2+\left(x+y+2z\right)^2-16z^2\)
\(=\left(x+y-2z\right)^2+\left(x+y+2z-4z\right)\left(x+y+2z+4z\right)\)
\(=\left(x+y-2z\right)^2+\left(x+y-2z\right)\left(x+y+6z\right)\)
\(=\left(x+y-2z\right)\left(x+y-2z+x+y+6z\right)\)
\(=\left(x+y-2z\right)\left(2x+2y+4z\right)\)
\(=2\left(x+y-2z\right)\left(x+y+2z\right)\)
7,\(=a^2x^2+6axy+9y^2-\left(-6ax^2-6ay^2+x^2+y^2\right)+9x^2-6axy+a^2y^2\)
\(=a^2x^2+6axy+9y^2+6ax^2+6ay^2-x^2-y^2+9x^2-6axy+a^2y^2\)
\(=a^2x^2+6ax^2+8x^2+a^2y^2+6ay^2+8y^2\)\(=x^2\left(a^2+6a+8\right)+y^2\left(a^2+6a+8\right)\)
\(=\left(x^2+y^2\right)\left(a^2+6a+8\right)\)\(=\left(x^2+y^2\right)\left(a^2+2a+4a+8\right)\)
\(=\left(x^2+y^2\right)\left[a\left(a+2\right)+4\left(a+2\right)\right]=\left(x^2+y^2\right)\left(a+2\right)\left(a+4\right)\)
a, 4x - 1 = 3x - 2
b, x + 1 = 2( x - 3)
c, 2( x + 1) + 3 = 2-x ?
a) 4x - 1 = 3x - 2
<=> 4x - 3x = -2 + 1
<=> x = -1
Vậy S = {-1}
b) x + 1 = 2. (x - 3)
<=> x + 1 = 2x - 6
<=> x - 2x = -6 -1
<=> -x = -7
<=> x = 7
Vậy:....
c) 2. (x + 1) + 3 = 2 - x
<=> 2x + 2 + 3 = 2 - x
<=> 2x + x = 2 - 2 - 3
<=> 3x = -3
<=> x = -1
Vậy:,,,,
a, 4x-1=3x-2 b, x+1=2(x-3)
4x-3x= -2+1 x+1=2x-6
x = -1 x-2x=-6-1
Vậy Tập nghiệm S =( -1 ) -x = -7
x=7
Vậy tập nghiệm S =(7)
c, 2(x+1)+3=2-x
2x+2+3=2-x
2x+5 =2-x
2x+x =2-5
3x = -3
x -1
Vậy tập nghiệm S = (-1)
a) 4x -1 = 3x -2
<=> 4x - 3x = - 2 + 1
<=> x = -1
Vậy tập nghiệm S ={-1}
b) x + 1 = 2(x - 3)
<=> x+1 = 2x - 6
<=> 1 + 6 = 2x - x
<=> x = 7
Vậy tập nghiệm S ={7}
c) 2(x+1) + 3 = 2-x
<=> 2x + 2 + 3 = 2 - x
<=> 2x + x = 2 - 2 - 3
<=> 3x = -3
<=> x = -1
Vậy tập nghiệm S ={-1}
giải phương trình:
a)(x+5)(x+2)-3(4x-3)=(x-5)^2
b)(x+2)(4-x)=x^2+4x+4
c)x+2/x+1-3/2-x=3/x^2-x-2+1
a, \(x^2+7x+10-12x+9=x^2-10x+25\)
\(\Leftrightarrow5x=6\Leftrightarrow x=\dfrac{6}{5}\)
b, bạn ktra lại đề nhé
c, \(x^2-4+3x+3=3+x^2-x-2\)
\(\Leftrightarrow x^2+3x-1=x^2-x+1\Leftrightarrow4x=2\Leftrightarrow x=\dfrac{1}{2}\left(tm\right)\)
Phân tích đa thức thành nhân tử
a, 5a^2 - 5b^2
b,2ab^2 - a^2b - b^3
c, a^3+ a^2b - ab^2 - b^3
d, x^3 + x^2 - 4x - 4
e, x^4 - 4x^3 + 4x^2
f, x^3 - x^2 - x - 1
a, \(5a^2-5b^2=5\left(a^2-b^2\right)=5\left(a+b\right)\left(a-b\right)\)
b, \(2ab^2-a^2b-b^3=b\left(2ab-a^2b-b^2\right)=-b\left(a^2-2ab+b^2\right)\)
\(=-b\left(a-b\right)^2\)
a) 5a2 - 5b2 = 5(a2-b2) = ( a+b) (a-b)
b) 2ab2 - a2b - b3 = b ( 2ab-a2-b2 ) = -b (a2-2ab+b2) = -b (a-b)2
c: \(=\left(a-b\right)\left(a^2+ab+b^2\right)+ab\left(a-b\right)\)
\(=\left(a-b\right)\left(a^2+2ab+b^2\right)=\left(a-b\right)\left(a+b\right)^2\)
d: \(=x^2\left(x+1\right)-4\left(x+1\right)=\left(x+1\right)\left(x-2\right)\left(x+2\right)\)
e: \(=x^2\left(x^2-4x+4\right)=x^2\left(x-2\right)^2\)
a) 4(x-3)(x+3) -1 + 4x + (3+2x)2
b) 1 - (-2x+3)2 = (x-1)(x+2) -6
1.\(\sqrt{x^2-4x+3}=x-2\)
2.\(\sqrt{4x^2-4x+1}=x-1\)
3. \(2x-\sqrt{4x-1}=0\)
4. \(x-2\sqrt{x-1}=16\)
1. \(\sqrt{x^2-4x+3}=x-2\)
<=> x2 - 4x + 3 = (x - 2)2
<=> x2 - 4x + 3 = x2 - 4x + 4
<=> x2 - x2 - 4x + 4x = 1
<=> 0 = 1 (Vô lí)
vậy PT có nghiệm là S = \(\varnothing\)
2. \(\sqrt{4x^2-4x+1}=x-1\)
<=> \(\sqrt{\left(2x-1\right)^2}=x-1\)
<=> 2x - 1 = x - 1
<=> 2x - x = -1 + 1
<=> x = 0
1: ta có: \(\sqrt{x^2-4x+3}=x-2\)
\(\Leftrightarrow x^2-4x+3=x^2-4x+4\)(vô lý)
2: Ta có: \(\sqrt{4x^2-4x+1}=x-1\)
\(\Leftrightarrow\left(2x-1-x+1\right)\left(2x-1+x-1\right)=0\)
\(\Leftrightarrow x\left(3x-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\left(loại\right)\\x=\dfrac{2}{3}\left(loại\right)\end{matrix}\right.\)