1.Rút gọn biểu thức:

\(a,\)\(x\times\left(2x^2-3\right)-x^2\left(5x+1\right)+x^2\)

\(b,\)\(3x\times\left(x-2\right)-5x\times\left(1-x\right)-8\times\left(x^2-3\right)\)

\(c,\)\(\left(2x-6\right)\times\left(x+3\right)-5\times\left(2x^2-x+7\right)\)

\(\left(^{x^2}\times y\right)^{^5}\times\left(x^2\times y^2\right)^7\times\left(x\times y^2\right)^6\times x^3\)

Tìm x

a, \(\left(2-x\right)\times\left(\dfrac{4}{5}-x\right)< 0\)

b, \(\left(x-\dfrac{3}{2}\right)\times\left(2\times x-1\right)>0\)

c, \(\left(x-\dfrac{4}{7}\right)\div\left(x+\dfrac{1}{2}\right)>0\)

d, \(\left(2\times x-5\right)\div\left(x+1\dfrac{3}{4}\right)< 0\)

Giúp mk với

Rút gọn \(B=\left(x^4-x+\frac{x-3}{x^3+1}\times\frac{\left(x^3-2x^2+2x-1\right)\left(x+1\right)}{x^9+x^7-3x^2-3}+1-\frac{2\left(x+6\right)}{x^2+1}\right)\times\frac{4x^2+6x+1}{\left(x+3\right)\left(4-x\right)}\) 

Tìm x biết

a)\(\dfrac{2}{\left(x+2\right)\times\left(x+4\right)}+\dfrac{4}{\left(x+4\right)\times\left(x+8\right)}+\dfrac{6}{\left(x+8\right)\times\left(x+14\right)}=\dfrac{x}{\left(x+2\right)\times\left(x+14\right)}\)

cho: \(f\left(x\right)=a\times x^3+4\times x\times\left(x^2-1\right)+8\)

\(g\left(x\right)=x^3-4\times x\times\left(b\times x+1\right)+c-3\)

tìm a, b, c để \(f\left(x\right)=g\left(x\right)\)

Tìm x  \(\frac{2}{\left(x-1\right)\times\left(x-3\right)}+\frac{5}{\left(x-3\right)\times\left(x-8\right)}+\frac{12}{\left(x-8\right)\times\left(x-20\right)}-\frac{1}{x-20}=-\frac{3}{4}\)-3/4