a: \(\left(\dfrac{3}{2}x-1\right)\left(-4x^2+2x-6\right)\)
\(=-6x^3+3x^2-9x+4x^2-2x+6\)
\(=-6x^3+7x^2-11x+6\)
b: \(=5x\left(x^2-4x+3\right)+4x^3-8x^2\)
\(=5x^3-20x^2+15x+4x^3-8x^2\)
\(=9x^3-28x^2+15x\)
Tìm x biết : (đề không sai)
1.\(-4x\left(x-7\right)+4x\left(x^2-5\right)\) \(=28x^2-13\)
2.\(\left(4x^2-5x\right)\left(3x+2\right)-7x\left(x-7\right)\)= \(\left(-4+x\right)\left(-2x+3\right)+12x^3+2x^2\)
3.\(\left(-4x^2-3\right)\left(2x+5\right)-\left(8x-3\right)\) \(\left(-x^2+2\right)=-5x^2\left(x-6\right)-3x^2-4\)
4.\(\left(x-7\right)\left(x+5\right)-\left(x-3\right)\left(x-2\right)\) \(=15x^2\left(x+1\right)-\left(3x^2-1\right)\) \(\left(5x^2-2\right)-21x^2\)
5.\(\left(x-3\right)\left(-x+10\right)+\left(x-8\right)\left(x+3\right)\) \(=\left(5x^2-1\right)\left(x+3\right)-5x^3-15x^2\)
6.\(\left(-2x^2+5\right)\left(-x+3\right)-x^2\left(2x-6\right)\) \(=\left(x-1\right)\left(x+1\right)-\left(x-2\right)\left(x+4\right)\)
Tìm x:
a.\(5x-3\left\{4x-2\left[4x-3(5x-2)\right]\right\}=182\)
b.\(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+5\right)=0\)
c.\(\left(2x+3\right)\left(x-4\right)+\left(x-5\right)\left(x-2\right)=\left(3x-5\right)\left(x-4\right)\)
Giúp mk vs!!
I) Tính (rút gọn)
1) \(\left(x^2-2x-1\right).\left(x-3\right)\)
2) (x - 5).\(\left(-x^2+4x-1\right)\)
3) \(\left(\frac{1}{2}x+3\right).\left(2x^2-4x-6\right)\)
4) \(\left(2x-1\right).\left(x^2-5x+3\right)\)
5) \(\left(-x+4\right).\left(-x^2+4x-1\right)\)
(Bn nào làm đc câu nào thì làm nha)
tìm x, biết:
\(a,-4x\left(x-7\right)+4x\left(x^2-5\right)=28x^2-13\)
\(b,\left(4x^2-5x\right)\left(3x+2\right)-7x\left(x+5\right)\) \(=\left(-4+x\right)\left(-2x+3\right)+12x^2+2x^2\)
a\(8\left(x+\dfrac{1}{x}\right)^{2^{ }}+4\left(x^{2^{ }}+\dfrac{1}{x^2}\right)-4\left(x^2+\dfrac{1}{x^2}\right)\left(x+\dfrac{1}{x}\right)=\left(x+4\right)^2\)giải các phương trình\(\dfrac{x+4}{2x^2-5x+2}+\dfrac{x+1}{2x^2-7x+3}=\dfrac{2x+5}{2x^2-7x+3}\)
Thực hiện phép tính :
a) \(\left(\dfrac{1}{2}x-1\right)\left(2x-3\right)\)
b) \(\left(x-7\right)\left(x-5\right)\)
c) \(\left(x-\dfrac{1}{2}\right)\left(x+\dfrac{1}{2}\right)\left(4x-1\right)\)
giải các bất phương trình sau:
a) 3x-5 > 2(x-1)+x
b)\(\left(x+2\right)^2-\left(x-2\right)^2>8x-2\)
c)3(4x+1) - 2(5x+2)≥ 8x-2
d)\(2x^2+2x+1-\dfrac{15\left(x+1\right)}{2}\le2x\left(x+1\right)\)
Thực hiện phép tính :
a) (x-1)(x+1)(x+2)
b) \(\dfrac{1}{2}x^2y^2\left(2x+y\right)\left(2x-y\right)\)
c)\(\left(x-\dfrac{1}{2}\right)\left(x+\dfrac{1}{2}\right)\left(4x-1\right)\)
Thực hiện các phép tính sau:
a).\(\left(\dfrac{2x+1}{2x-1}-\dfrac{2x-1}{2x+1}\right):\dfrac{4x}{10x-5}\)
b). \(\left(\dfrac{1}{x^2+1}-\dfrac{2-x}{x+1}\right):\left(\dfrac{1}{x}+x-2\right)\)
c). \(\dfrac{1}{x-1}-\dfrac{x^3-x}{x^2+1}.\left(\dfrac{1}{x^2-2x+1}+\dfrac{1}{1-x^2}\right)\)
d). \(\left(\dfrac{x^2+xy}{x^3+x^2y+xy^2+y^3}+\dfrac{y}{x^2+y^2}\right):\left(\dfrac{1}{x-y}-\dfrac{2xy}{x^3-x^2y+xy^2-y^3}\right)\)
Tìm x :
\(\left(2x^2+1\right)\cdot\left(3x^2-1\right)-\left(4x^2-3\right)\cdot\left(x^2+1\right)=x\cdot\left(2x^2+1\right)\)
