Rút gọn
a) \(\left(x^2-1\right)^3-\left(x^4+x^2+1\right)\left(x^2-1\right)\)
b) \(\left(x^4-3x^2+9\right)\left(-x^2+3\right)-\left(3+x^2\right)^3\)
c) \(\left(x+y\right)^3-\left(x-y\right)^3-6x^2y\)
1)rút gọn
a) (x+5)(\(x^2\) - 5x + 25) - \(\left(x+3\right)^3\) + (x-2)(\(x^2\) + 2x + 4) - \(\left(x-1\right)^3\)
b)\(\left(x+3y\right)^3+\left(3x+2y\right)\left(9x^2-6xy+4y^2\right)-\left(2y-3x\right)^3\)
c)\(\left(3x+y\right)^3-\left(5x-y\right)\left(25x^2+5xy+y^2\right)+\left(x+2y\right)^3\)
2)tìm x,biết
a)\(\left(x-1\right)^2-\left(x-2\right)\left(x+3\right)+\left(x+2\right)^3=\left(x-3\right)\left(x^2+3x+9\right)+6x\left(x+2\right)\)
Cảm ơn các bạn ^^
Rút gọn:
a) \(\dfrac{3\left(x-y\right)\left(x-z\right)^2}{6\left(x-y\right)\left(x-z\right)}\)
b) \(\dfrac{6x^2y^2}{8xy^5}\)
c) \(\dfrac{3x\left(1-x\right)}{2\left(x-1\right)}\)
d) \(\dfrac{9-\left(x+5\right)^2}{x^2+4x+4}\)
e) \(\dfrac{x^2-2x+1}{x^2-1}\)
f) \(\dfrac{8x-4}{8x^3-1}\)
g) \(\dfrac{x^2+5x+6}{x^2+4x+4}\)
k) \(\dfrac{20x^2-45}{\left(2x+3\right)^2}\)
a: \(=\dfrac{x-z}{2}\)
b: \(=\dfrac{3x}{4y^3}\)
Rút gọn biểu thức:
a) \(A=\left(x-y\right)^3+\left(y+x\right)^3+\left(y-x\right)^3-3xy\left(x+y\right)\)
b) \(B=3x^2\left(x+1\right)\left(x-1\right)-\left(x^2-1\right)\left(x^4+x^2+1\right)+\left(x^2-1\right)^3\)
c) \(C=\left(x+y\right)\left(x^2-xy+y^2\right)+\left(x-y\right)\left(x^2+xy+y^2\right)-2x^3\)
d) \(D=\left(x+1\right)^3+\left(x-1\right)^3+x^3-3x\left(x+1\right)\left(x-1\right)\)
Rút gọn phân thức
a,\(\dfrac{\left(x^2-y\right).\left(y+1\right)+x^2y^2-1}{\left(x^2+y\right).\left(y+1\right)+x^2y^2+1}\)
b,\(\dfrac{x^2\left(y-z\right)+y^2\left(z-x\right)+z^2\left(x+y\right)}{x^2y-x^2z+y^2z-y^3}\)
c, \(\dfrac{x^3+3x^2-4}{x^3-3x+2}\)
d , \(\dfrac{x^4+6x^3+9x^2-1}{x^4+6x^3+7x^2-6x+1}\)
1.rút gọn biểu thuc P=\(\dfrac{2}{x+3}+\dfrac{1}{x-3}+\dfrac{9-x}{9-x^2}\) với x\(\ne-3vàx\ne3\)
2.thực hiện phép tính \(\left(2x^4-3x^3-3x^2+6x-1\right):\left(x^2-2\right)\)
\(\left(15x^4y^6-12^3y^4-18x^2y^3\right):\left(-6x^2y^2\right)\)
Rút gọn các biểu thức:
\(A=\left(x+3\right)\left(x^2-3x+9\right)-\left(54+x^3\right)\)
\(B=\left(2x+y\right)\left(4x^2-2xy+y^2\right)-\left(2x-y\right)\left(4x^2+2xy+y^2\right)\)
\(C=\left(2x+1\right)^2+\left(1-3x\right)^2+2\left(2x+1\right)\left(3x-1\right)\)
\(D=\left(x-2\right)\left(x^2+2x+4\right)-\left(x+1\right)^3+3\left(x-1\right)\left(x+1\right)\)
a)
\(A=\left(x+3\right)\left(x^2-3x+9\right)-\left(54+x^3\right)\)
\(=x^3-3x^2+9x+3x^2-9x+27-54-x^3\)
\(=-27\)
or
\(A=x^3+27-54-x^3=-27\)
b)
\(B=\left(2x+y\right)\left(4x^2-2xy+y^2\right)-\left(2x-y\right)\left(4x^2+2xy+y^2\right)\)
\(=8x^3+y^3-8x^3+y^3=2y^3\)
c)
\(C=\left(2x+1\right)^2+\left(1-3x\right)^2+2\left(2x+1\right)\left(3x-1\right)\)
\(=\left(2x+1+3x-1\right)^2=\left(5x\right)^2=25x^2\)
d)
\(D=\left(x-2\right)\left(x^2+2x+4\right)-\left(x+1\right)^3+3\left(x-1\right)\left(x+1\right)\)
\(=x^3-8-\left(x-1\right)^3+3\left(x-1\right)\left(x+1\right)\)
\(=6x^2-3x-10\)
rút gọn các phân thức
a,\(\dfrac{7xy^3\left(x-2y\right)}{14x^2y^2\left(x-2y\right)^2}\)
b,\(\dfrac{4a^2-8ab}{2\left(2b-a\right)^3}\)
c,\(\dfrac{3x^3-3x}{x^4-1}\)
d,\(\dfrac{45x\left(3-x\right)}{15x\left(x-3\right)^3}\)
c: \(=\dfrac{3x\left(x-1\right)\left(x+1\right)}{\left(x-1\right)\left(x+1\right)\left(x^2+1\right)}=\dfrac{3x}{x^2+1}\)
Rút gọn
a) \(x.\left(x+4\right).\left(x-4\right)-\left(x^2+1\right).\left(x-1\right)\)
b) \(\left(y-3\right).\left(y+3\right).\left(y^2+9\right)-\left(y^2+2\right).\left(y^2-2\right)\)
a) \(x\left(x^2-16\right)-\left(x^2+1\right)\left(x-1\right)\) =\(x^3-16x^2-x^3+x^2-x+1\)
= \(x^2-17x+1\)
b) \(\left(y^2-9\right)\left(y^2+9\right)-\left(y^4-4\right)\) = \(\left(y^4-81\right)-\left(y^4-16\right)\)
=\(-65\)
Rút gọn \(B=\left(x^4-x+\frac{x-3}{x^3+1}\times\frac{\left(x^3-2x^2+2x-1\right)\left(x+1\right)}{x^9+x^7-3x^2-3}+1-\frac{2\left(x+6\right)}{x^2+1}\right)\times\frac{4x^2+6x+1}{\left(x+3\right)\left(4-x\right)}\)