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6 tháng 7 2018

\(\frac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}=\frac{\left(3x^3-3x^2\right)-\left(4x^2-4x\right)+\left(x-1\right)}{\left(2x^3-2x^2\right)+\left(x^2-x\right)-\left(3x-3\right)}=\frac{\left(x-1\right).\left(3x^2-4x+1\right)}{\left(x-1\right).\left(2x^2+x-3\right)}\\ \)

\(=\frac{3x^2-4x+1}{2x^2+x-3}=\frac{\left(3x^2-3x\right)-\left(x-1\right)}{\left(2x^2-2x\right)+\left(3x-3\right)}=\frac{\left(x-1\right).\left(3x-1\right)}{\left(x-1\right).\left(2x+1\right)}=\frac{3x-1}{2x+1}\)

6 tháng 7 2018

\(\frac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}\)

\(=\frac{3x^3-3x^2-4x^2+4x+x-1}{2x^3-2x^2+x^2-x-3x+3}\)

\(=\frac{\left(3x^3-3x^2\right)-\left(4x^2-4x\right)+\left(x-1\right)}{\left(2x^3-2x^2\right)+\left(x^2-x\right)-\left(3x-3\right)}\)

\(=\frac{3x^2\left(x-1\right)-4x\left(x-1\right)+\left(x-1\right)}{2x^2\left(x-1\right)+x\left(x-1\right)-3\left(x-1\right)}\)

\(=\frac{\left(3x^2-4x+1\right)\left(x-1\right)}{\left(2x^2+x-3\right)\left(x-1\right)}\)

\(=\frac{3x^2-4x+1}{2x^2+x-3}\)

\(=\frac{3x^2-3x-x+1}{2x^2-2x+3x-3}\)

\(=\frac{\left(3x^2-3x\right)-\left(x-1\right)}{\left(2x^2-2x\right)-\left(3x-3\right)}\)

\(=\frac{3x\left(x-1\right)-\left(x-1\right)}{2x\left(x-1\right)-3\left(x-1\right)}\)

\(=\frac{3x-1}{2x-3}\)

14 tháng 12 2020

ĐKXĐ: \(x\ne1;x\ne-\dfrac{3}{2}\)

Ta có: \(\dfrac{3x^3-7x^2+5x-1}{2x^3-x^2-4x+3}=\dfrac{\left(x-1\right)^2\left(3x-1\right)}{\left(x-1\right)^2\left(2x+3\right)}=\dfrac{3x-1}{2x+3}\)

 

1: \(=6x^2+2x-15x-5-x^2+6x-9+4x^2+20x+25-27x^3-27x^2-9x-1\)

=-27x^3-18x^2+4x+10

2: =4x^2-1-6x^2-9x+4x+6-x^3+3x^2-3x+1+8x^3+36x^2+54x+27

=7x^3+37x^2+46x+33

5:

\(=25x^2-1-x^3-27-4x^2-16x-16-9x^2+24x-16+\left(2x-5\right)^3\)

\(=8x^3-60x^2+150-125+12x^2-x^3+8x-60\)

=7x^3-48x^2+8x-35

25 tháng 8 2016

a) 5x2 ( 3x2 -7x+2)-15x(x-3)

=15x4-35x3+10x2-15x2+45x

=15x4-35x3-5x2+45x

c) (x+3)(x-3)(x-2)(x+1)

=(x2-9)(x2+x-2x-2)

=(x2-9)(x2-x-2)

=x4-x3-2x2-9x2+9x+18

=x4-x3-11x2+9x+18

d)(2x+1)2+(4x-1)2+2(2x+1)(4x+1)

=2x2+4x+1-16x2-8x+1

=2x2+4x+1-16x2-8x+1+16x2-4x+8x-2

=2x2+7

e) (2x2-3x)(5x2-2x+1)-10x2(x+3)

=10x4 -4x3+2x2-15x3+6x2-3 -10x2-30x

=10x4-19x3-2x2-30x-3

26 tháng 8 2016

thanks bn nka

29 tháng 4 2020

\(\frac{3x^3-7x^2+5x+1}{2x^3-x^2-4x+3}\)

\(\frac{\left(3x^2-4x+1\right)\left(x-1\right)}{\left(2x^2+x-3\right)\left(x-1\right)}\)

\(\frac{\left(3x^2-x-3x+1\right)\left(x-1\right)}{\left(2x^2+3x-2x-3\right)\left(x-1\right)}\)

\(\frac{\left[x\left(3x-1\right)-\left(3x-1\right)\right]\left(x-1\right)}{\left[x\left(2x+3\right)-\left(2x+3\right)\right]\left(x-1\right)}\)

\(\frac{\left(3x-1\right)\left(x-1\right)\left(x-1\right)}{\left(2x+3\right)\left(x-1\right)\left(x-1\right)}\)

\(\frac{\left(3x-1\right)\left(x-1\right)^2}{\left(2x+3\right)\left(x-1\right)^2}\)

\(\frac{3x-1}{2x+3}\)

1 tháng 8 2020

\(F=-3\left(x-8\right)\left(2x+1\right)-\left(x+5\right)\left(2-3x\right)-4x\left(x-6\right)\)

\(=-3\left(-3-8\right)\left(-6+1\right)-\left(5-3\right)\left(2+9\right)+12\left(-9\right)\)

\(=-3\left(-11\right)\left(-5\right)-\left(-2\right)11-12.9\)

\(=-165+22-108=22-273=-251\)

\(G=\left(5x-4\right)\left(5-2x\right)-7x\left(x^2-4x+3\right)+\left(x^2-4x\right)\left(7x-2\right)\)

\(=\left(5-4\right)\left(5-2\right)-7\left(1-4+3\right)+\left(1-4\right)\left(7-2\right)\)

\(=3-7.0+5.\left(-3\right)=3-15=-12\)

\(H=\left(-3x+5\right)\left(x-6\right)-\left(x-1\right)\left(x^2-2x+3\right)+\left(x+2\right)\left(x^2-3\right)\)

\(=\left(3+5\right)\left(-1-6\right)-\left(-1-1\right)\left(1+2+3\right)+\left(-1+2\right)\left(1-3\right)\)

\(=8\left(-7\right)-\left(-2\right)6+1\left(-2\right)=-56+12-2=-46\)

1 tháng 8 2020

\(L=5x\left(x-1\right)\left(2x+3\right)-10x\left(x^2-4x+5\right)-\left(x-1\right)\left(x-4\right)\)

\(=-\frac{5}{3}\left(-\frac{4}{3}\right)\left(-\frac{2}{3}+3\right)+\frac{10}{3}\left(\frac{1}{9}+\frac{4}{3}+5\right)-\left(-\frac{4}{3}\right)\left(-\frac{1}{3}-4\right)\)

\(=\frac{20}{9}\left(\frac{7}{3}\right)+\frac{10}{3}\left(\frac{13}{9}+5\right)+\frac{4}{3}\left(-\frac{13}{3}\right)\)

\(=\frac{140}{27}+\frac{10}{3}.\frac{58}{9}-\frac{52}{9}\)

\(=\frac{140}{27}+\frac{580}{27}-\frac{156}{27}=\frac{140+580-156}{27}=\frac{720-156}{27}=\frac{564}{27}\)

\(M=-7x\left(x-5\right)-\left(x-1\right)\left(x^2-x-2\right)+x^2\left(x-3\right)-5x\left(x-8\right)\)

\(=\frac{-7}{2}\left(\frac{1}{2}-5\right)+\frac{\left(\frac{1}{4}-\frac{1}{2}-2\right)}{2}+\frac{1}{4}\left(\frac{1}{2}-3\right)-\frac{5}{2}\left(\frac{1}{2}-8\right)\)

\(=\frac{7}{2}.\frac{9}{2}-\frac{9}{8}-\frac{1}{4}.\frac{5}{2}+\frac{5}{2}.\frac{15}{2}\)

\(=\frac{63}{4}-\frac{9}{8}-\frac{5}{8}+\frac{75}{4}=\frac{138}{4}-\frac{7}{4}=\frac{131}{4}\)

28 tháng 6 2021

a) (7x - 8)(7x + 8) - 10(2x + 3)2 + 5x(3x - 2)2 - 4x(x - 5)2

= 49x2 - 64 - 10(4x2 + 12x + 9) + 5x(9x2 - 12x + 4)  - 4x(x2  - 10x + 25)

= 49x2 - 64 - 40x2 - 120x - 90 + 45x3 - 60x2 + 20x - 4x3 + 40x - 100x

= 41x3 - 51x2 - 160x - 154

b) (x2 - 3)(x2 + 3) - 5x2(x + 1)2 - (x2 - 3x)(x2 - 2x) + 4x(x + 2)2

= x4 - 9 - 5x2(x2 + 2x + 1) - x4 + 5x3 - 6x2 + 4x(x2 + 4x + 4)

= 5x3 - 6x2 - 5x4 - 10x3 - 5x2 + 4x3 + 16x2 + 16x - 9

= -5x4 - x3 + 5x2 + 16x - 9

28 tháng 6 2021

Trả lời:

a , ( 7x - 8 ) ( 7x + 8 ) - 10 ( 2x + 3 )+ 5x ( 3x - 2 )- 4x ( x - 5 )2

= 49x2 - 64 - 10 ( 4x2 + 12x + 9 ) + 5x ( 9x2 - 12x + 4 ) - 4x ( x2 - 10x + 25 )

= 49x2 - 64 - 40x2 + 120x - 90 + 45x3 - 60x2 + 20x - 4x3 + 40x2 - 100x

= 41x3 - 11x2 + 40x - 154

b , ( x- 3 ) ( x+ 3 ) - 5x( x + 1 )- ( x- 3x ) ( x- 2x ) + 4x ( x + 2 )2

= x4 - 9 - 5x2 ( x2 + 2x + 1 ) - ( x4 - 2x3 - 3x3 + 6x2 ) + 4x ( x2 + 4x + 4 )

= x4 - 9 - 5x4 - 10x3 - 5x2 - x4 + 2x3 + 3x3 - 6x2 + 4x3 + 16x2 + 16x

= - 5x4 - x3 + 5x+ 16x - 9