Question

giải phương trình

Answer 1

b,d mình giải rồi nhé

\(f,\left(x-1\right)^3-x\left(x+1\right)^2=5x\left(2-x\right)-11\left(x+2\right)\\ =>x^3-3x^2+3x-1-x\left(x^2+2x+1\right)=10x-5x^2-11x-22\\ =>x^3-3x^2+3x-1-x^3-2x^2-x-10x+5x^2+11x+22=0\\ =>3x+21=0\\ =>x=-7\)

\(h,\left(x-3\right)\left(x+4\right)-2\left(3x-2\right)=\left(x-4\right)^2\\ =>x^2-3x+4x-12-6x+4-x^2+8x-16=0\\ =>x-24=0\\ =>x=24\)

\(j,\left(x+1\right)\left(x^2-x+1\right)-2x=x\left(x+1\right)\left(x-1\right)\\ =>x^3+1-2x=x\left(x^2-1\right)\\ =>x^3-2x+1-x^3+x=0\\ =>-x=-1\\ =>x=1\)

Answer 2

b: =>2x(x^2+4x+4)-8x^2=2(x^3-8)

=>2x^3+8x^2+8x-8x^2=2x^3-16

=>8x=-16

=>x=-2

d: \(\Leftrightarrow x^3-6x^2+12x-8+9x^2-1=x^3+3x^2+3x+1\)

=>3x^2+12x-9=3x^2+3x+1

=>12x-9=3x+1

=>9x=10

=>x=10/9

j: =>x^3+1-2x=x(x^2-1)

=>x^3-x=x^3-2x+1

=>-x=-2x+1

=>x=1

h: =>x^2+x-12-6x+4=x^2-8x+16

=>-7x-8=-8x+16

=>x=24

f: \(\Leftrightarrow x^3-3x^2+3x-1-x^3-2x^2-x=10x-5x^2-11x-22\)

=>\(-5x^2+2x-1=-5x^2-x-22\)

=>2x-1=-x-22

=>3x=-21

=>x=-7