A= x(4-x)+(x-2)2
1) Làm tính nhân: a) (3-2*x+4*x^2)*(1+x-2*x^2). b) (a^2+a*x+x^2)*(a^2-a*x+x^2)*(a-x). 2) Cho đa thức: A=19*x^2-11*x^3+9-20*x+2*x^4. B=1+x^2-4*x Tìm đa thức Q và R sao cho A=B*Q+R. 3) Dùng hằng đẳng thức để làm phép chia: a) (4*x^4+12*x^2*y^2+9*y^4):(2*x^2+3*y^2). b) ( 64*a^2*b^2-49*m^4*n^2):(8*a*b+7*m^2*n). c) (27*x^3-8*y^6):(3*x-2*y^2)
Bạn viết như vậy vẫn nhìn đc nhưng nhìn hơi khó
Thì các bạn vít ra giấy là hỉu nk mong giải giúp mk cái
3x^4 + 3x^2y^2 + 6x^3y - 27x^2
x^4 + x^3 - x^2 + x
2x^5 - 6x^4 - 2a^2x^3 - 6ax^3
x^5 + x^4 + x^3 + x^2 + x + 1
x^3 - 1 + 5x^2 - 5 + 3x - 3
1/4.(a + 1)^2 - 4/9.(a - 2)^2
12a^2b^2 - 3.(a^2b^2)^2
4x^2y^2 - (x^2 + y^2 - a^2)^2
(a + b + c)^2 + (a + b - c)^2 - 4c^2
x^3 - 1 + 5x^2 - 5 + 3x - 3
phân tích đa thức thành nhân tử
1/(x+2)(x+3)(x+4)(x+5)-24
2/(x^2+x)^2+4(x^2+x)-12
3/(x^2+x+1)(x^2+x+2)-12
4/(a^2-4)(a^2+6a+5)
1/(x+2)(x+3)(x+4)(x+5)-24
=(x+2)(x+5)(x+3)(x+4)
=(x+2)(x-2+7)(x+3)(x-3+7)
=[(x+2)(x-2)+7x+14][(x+3)(x-3)+7x+21]
=(x2-4+7x+14)(x2-9+7x+21)
=(x2+10+7x)(x2+12+7x)
2/(x2+x)2+4(x2+x)-12
=(x2+x)2+4(x2+x)+22-16
=(x2+x+2)2-42
=(x2+x+2+4)(x2+x+2-4)
=(x2+x+6)(x2+x-2)
3/(x2+x+1)(x2+x+2)-12
=(x2+x+1)(x2+x+-1+3)-12
=(x2+x+1)(x2+x+-1)+3(x2+x+1)-12
=(x2+x)-1+3(x2+x)+3-12
=(x2+x)(x2+x+3)-10
làm đến đây thì mk bí, bạn giúp suy nghĩ nốt nha
4/nó là nhân tử sẵn rồi mà
\(3/\)
\(\left(x^2+x+1\right)\left(x^2+x+2\right)-12\)
\(=\left(x^2+x+1\right)\left(x^2+x+1+1\right)-12\)
\(=\left(x^2+x+1\right)^2+x^2+x+1-12\)
\(=\left(x^2+x+1\right)^2+4\left(x^2+x+1\right)-3\left(x^2+x+1\right)-12\)
\(=\left(x^2+x+1\right)\left(x^2+x+1+4\right)-3\left(x^2+x+1+4\right)\)
\(=\left(x^2+x+1-3\right)\left(x^2+x+1+4\right)\)
\(=\left(x^2+x-2\right)\left(x^2+x+5\right)\)
. Bài 1:Phân tích
a: A=4y^2-(x^2-10x+25)
b: B=(x-4)^4-(x+a)^4
c: C=(x^2+x)^2+2.(x^2+x)+1
. Bài 2 Tính giá trị biểu thức
a A=(x^2-2xy+y^2)-4z^2 với x=6;y=2;z=25
b B=(x^2+y^2-5)^2-4.(xy-2)^2 với x=2014;y=2015
\(A=4y^2-\left(x^2-10x+25\right)\)
\(A=4y^2-\left(x-5\right)^2\)
\(A=\left(2y-x-5\right)\left(2y+x-5\right)\)
\(B=\left(x-4\right)^4-\left(x+a\right)^4\)
\(B=\left(\left(x-4\right)^2\right)^2-\left(\left(x+a\right)^2\right)^2\)
\(B=\left(\left(x-4\right)^2-\left(x+a\right)^2\right)\left(\left(x-4\right)^2+\left(x+a\right)^2\right)\)
\(B=\left(x-4\right)\left(x+a\right)\left(\left(x-4\right)^2+\left(x+a\right)^2\right)\)
\(C=\left(x^2+x\right)^2+2\left(x^2+x\right)+1\)
\(C=\left(x^2+x\right)\left(x^2+x+2\right)+1\)
\(A=\left(x^2-2xy+y^2\right)-4z^2\)
\(A=\left(x-y\right)^2-4z^2\)
\(A=\left(x-y-2z\right)\left(x-y+2z\right)\)
Thay x,y,z vào , ta dc;
\(A=\left(6-2-2.25\right)\left(6-2+2.25\right)\)
\(A=-2484\)( k bik bấm máy tính đúng k? bn kiểm tra lại nhé!)
. Bạn ơi câu 1C ý hình như sai.
C = (x^2+x)^2+2.(x^2+x)+1
C = ((x^2+x)+1)^2
. Mình không biết là ai sai nữa TvT
1) Tính nhanh :
a) 1,6^2-(1,24^2-2,48*0,24+0,24^2)
b) 18,7^2+3,3^2-6,7^2-13,3^2
2) Tính:
a) (x^2+x+1)*(x^2-x-1)
b) (x^2+x*y+y^2)*(x^2-x*y+y^2)
3) Phân tích đa thức thành nhân tử:
a) x^2-y^2-4*x+4
b) (a+b)^2 -(a-b)^2
c) 4*x^2*y^2-(x^2+y^2-z^2)^2
4) Giải phương trình :
a) (y+1)*(2-y)+(y-2)^2+y^2-4=0
b) x^3+x^2-4*x=4
1) Tính nhanh :
a) 1,6^2-(1,24^2-2,48*0,24+0,24^2)
b) 18,7^2+3,3^2-6,7^2-13,3^2
2) Tính:
a) (x^2+x+1)*(x^2-x-1)
b) (x^2+x*y+y^2)*(x^2-x*y+y^2)
3) Phân tích đa thức thành nhân tử:
a) x^2-y^2-4*x+4
b) (a+b)^2 -(a-b)^2
c) 4*x^2*y^2-(x^2+y^2-z^2)^2
4) Giải phương trình :
a) (y+1)*(2-y)+(y-2)^2+y^2-4=0
b) x^3+x^2-4*x=4
a,x^2+2x/(x+1)^2+3-x^2-2x/(x-1)^2+3=16/x^4+4x^2+16
b,x^2/x^2+2x+2+x^2/x^2-2x+2=5(x^2-5)/x^4+4+25/4
A= 6x/5x-20 - x/x^2-8x+16
A= 4/x+2 + 3/x-2 + 5x+2/4-x^2 - x^2-2x+4/x^3+8
A= ( 6x+1/x^2-6x) + 6x-1/x^2+6x) . x^2-36/x^2+1
A= ( x/x-1 - x+1/x) : ( x/x+1 - x-1/x)
oke nhé , giúp minh với
\(A=\dfrac{6x}{5x-20}-\dfrac{x}{x^2-8x+16}\)
\(ĐKXĐ:x\ne\pm4\)
\(\Leftrightarrow A=\dfrac{6x}{5\left(x-4\right)}-\dfrac{x}{\left(x-4\right)^2}\)
\(\Leftrightarrow A=\dfrac{6x^2-24x-5x}{5\left(x-4\right)^2}\)
\(\Leftrightarrow\dfrac{6x^2-29x}{5\left(x-4\right)^2}\)
\(\Leftrightarrow\dfrac{x\left(6x-29\right)}{5\left(x-4\right)^2}\)
\(A=\left(\dfrac{x}{x-1}-\dfrac{x+1}{x}\right):\left(\dfrac{x}{x+1}-\dfrac{x-1}{x}\right)\)
\(ĐKXĐ:x\ne0;x\ne\pm1\)
\(\Leftrightarrow A=\left(\dfrac{x^2}{x\left(x-1\right)}-\dfrac{x^2-1}{x\left(x-1\right)}\right):\left(\dfrac{x^2}{x\left(x+1\right)}-\dfrac{x^2-1}{x\left(x+1\right)}\right)\)
\(\Leftrightarrow A=\dfrac{x\left(x+1\right)}{x\left(x-1\right)}\)
\(\Leftrightarrow A=\dfrac{x+1}{x-1}\)
\(A=\left[\dfrac{6x+1}{x^2-6x}+\dfrac{6x-1}{x^2+6x}\right].\dfrac{x^2-36}{x^2+1}\)
\(ĐKXĐ:x\ne0;x\ne\pm6\)
\(\Leftrightarrow A=\left[\dfrac{6x+1}{x\left(x-6\right)}+\dfrac{6x-1}{x\left(x+6\right)}\right].\dfrac{\left(x-6\right)\left(x+6\right)}{x^2+1}\)
\(\Leftrightarrow A=\left[\dfrac{\left(6x+1\right)\left(x+6\right)+\left(6x-1\right)\left(x-6\right)}{x\left(x-6\right)\left(x+6\right)}\right].\dfrac{\left(x-6\right)\left(x+6\right)}{x^2+1}\)
\(\Leftrightarrow A=\left[\dfrac{6x^2+37x+6+6x^2-37x+6}{x\left(x-6\right)\left(x+6\right)}\right].\dfrac{\left(x-6\right)\left(x+6\right)}{x^2+1}\)
\(\Leftrightarrow A=\dfrac{12\left(x^2+1\right)}{x\left(x-6\right)\left(x+6\right)}.\dfrac{\left(x-6\right)\left(x+6\right)}{x^2+1}\)
\(\Leftrightarrow A=\dfrac{12}{x}\)
A= 6x/5x-20 - x/x^2-8x+16
A= 4/x+2 + 3/x-2 + 5x+2/4-x^2 - x^2-2x+4/x^3+8
A= ( 6x+1/x^2-6x) + 6x-1/x^2+6x) . x^2-36/x^2+1
A= ( x/x-1 - x+1/x) : ( x/x+1 - x-1/x)
oke nhé , giúp minh với
a: \(=\dfrac{6x}{5\left(x-4\right)}-\dfrac{x}{\left(x-4\right)^2}\)
\(=\dfrac{6x^2-24x-5x}{5\left(x-4\right)^2}=\dfrac{6x^2-29x}{5\left(x-4\right)^2}\)
b: \(=\dfrac{4}{x+2}+\dfrac{3}{x-2}-\dfrac{5x+2}{\left(x-2\right)\left(x+2\right)}-\dfrac{x^2-2x+4}{x^3+8}\)
\(=\dfrac{4x-8+3x+6-5x-2}{\left(x+2\right)\left(x-2\right)}-\dfrac{1}{x+2}\)
\(=\dfrac{2x-2-x+2}{\left(x+2\right)\left(x-2\right)}\)
\(=\dfrac{x}{\left(x+2\right)\left(x-2\right)}\)
c: \(\left(\dfrac{x}{x-1}-\dfrac{x+1}{x}\right):\left(\dfrac{x}{x+1}-\dfrac{x-1}{x}\right)\)
\(=\dfrac{x^2-x^2+1}{x\left(x-1\right)}:\dfrac{x^2-x^2+1}{x\left(x+1\right)}\)
\(=\dfrac{x\left(x+1\right)}{x\left(x-1\right)}=\dfrac{x+1}{x-1}\)
Cho bt A=(x/x^2-4+1/x+2-2/x-2):(2-x+6/x+2) a)rut goc A b) tinh gt cua A khi x+-4
a,\(A=\left(\frac{x}{x^2-4}+\frac{1}{x+2}-\frac{2}{x-2}\right):\left(2-x+\frac{6}{x+2}\right)\)
\(=\left(\frac{x}{\left(x-2\right)\left(x+2\right)}+\frac{x-2}{\left(x+2\right)\left(x-2\right)}-\frac{2\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}\right):\left(\frac{-\left(x-2\right)\left(x+2\right)}{x+2}+\frac{6}{x+2}\right)\)
\(=\left(\frac{2x-2-2x+4}{\left(x+2\right)\left(x-2\right)}\right):\left(\frac{-\left(x^2-4\right)+6}{x+2}\right)\)
\(=\frac{2}{\left(x+2\right)\left(x-2\right)}.\frac{x-2}{-\left(x^2-4\right)+6}=\frac{2}{-\left(x+2\right)^2\left(x-2\right)+6}\)
Thay x = 4 ta được :
\(\frac{2}{-\left(4+2\right)^2\left(4-2\right)+6}=\frac{2}{-26}=-\frac{1}{13}\)
Tương tự với x = -4