3( x – 2 )^2 + 9( x – 1 ) = 3 (x^2 + x – 3 ) ( x + 3 )^2 – ( x – 3 )^2 = 6x + 18 ( x – 1)^3 – x( x+ 1 )^2 = 5x( 2 – x ) – 11( x + 2 ) ( x + 1 )( x^2 –

0 bình luận về “3( x – 2 )^2 + 9( x – 1 ) = 3 (x^2 + x – 3 ) ( x + 3 )^2 – ( x – 3 )^2 = 6x + 18 ( x – 1)^3 – x( x+ 1 )^2 = 5x( 2 – x ) – 11( x + 2 ) ( x + 1 )( x^2 –”

1. x-8=3-2(x+4)<=>x-8=3-2x-8<=>3x=3<=>x=1

   2(x+3)+3(x-1)=2<=>2x+6+3x-3=2<=>5x=5<=>x=1

   4(x-5)-3(x-1)=x-19<=>4x-20-3x+3=x-19<=>x=-2

   4)7 – ( x – 2) = 5(2x – 3)<=>7-x+2=10x-15<=>11x=22<=>x=2

   32 – 4(0,5y – 5) = 3y + 2<=>32-2y+20=3y+2<=>5y=50<=>y=10

   3(x – 1) – x = 2x – 3<=>3x-3-x=2x-3<=>0x=0(vô số nghiệm)

   x( x – 1) = x(x + 3)<=>x²-x=x²+3x<=>4x=0<=>x=0

   8x(2x –3) –x2 + 2 = x(x –5) –1<=>2x²-3x-x²+2=x²-5x-1<=>x=-3/2

   (x – 1)(x + 3) = x2 – 4<=>x²-3x-x-3=x²-4<=>4x=4<=>x=1

   2)(x – 5) = (x – 3)(x – 4)<=>x²-5x-2x+10=x²-4x-3x+12<=>0x=2(vô nghiệm) ( 6x + 2)(x – 2) = 2x(3x – 5)<=>6x²-12x+2x-4=6x²-10x<=>0x=-4(vô nghiệm)(x – 2)2 = (x – 3)(x + 2)<=>x²-4x+4=x²+2x-3x-6<=>x=10

   (x–1)(x +3) – (x+2)(x–3) = 0<=>x²-3x-x-3-x²+3x-2x+6=0<=>-3x=-3<=>x=1

   3x – 2)(4x + 3) = 2x(6x – 1)<=>12x²+9x-8x-6=12x²-2x<=>x=6

   4×2 – (2x + 1)(2x – 1) = 0<=>4x²-4x²+2x-2x+1=0<=>0x=-1(vô nghiệm)

   (x + 3)(x – 2) = (x + 1)2<=>x²-2x+3x-6=x²+2x+1<=>x(x+7)(x–7) + x2 – 2 = 2(x2+5)<=>x²-7x+7x-49+x²-2=2x²+10<=>0x=61(vô nghiệm)

   (x–1)2 + (x+3)2 = 2(x– 2)(x+2)<=>x²-2x+1+x²+6x+9=2x²+4x-4x-8<=>0x=-18(vô nghiệm)

    (x – 5)2 = (x + 3)2 + 2<=>x²-10x+25=x²+6x+9+2<=>16x=14<=>x=14/16

   (3x + 2)2 – (3x – 2)2 = 5x + 38<=>9x²+12x+4-9x²+12x-4=5x+38<=>19x=38<=>x=2

   chúc bạn học tốt!!!

    

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2.      3(x-2)² + 9(x-1) = 3(x²+x-3)

   ⇔ 3(x²-4x+4) + 9(x-1) = 3(x²+x-3)

   ⇔ 3x² – 12x + 12 + 9x – 9 = 3x² + 3x – 9

   ⇔ 3x² – 3x² – 12x + 9x – 3x = – 9 – 12 + 9

   ⇔ – 6x = – 12

   ⇔ x = 2.

        (x+3)² – (x-3)² = 6x + 18

   ⇔ (x+3-x+3)(x+3+x-3) = 6x + 18

   ⇔ 6(2x) = 6x + 18

   ⇔ 12x = 6x + 18

   ⇔ 12x – 6x = 18

   ⇔ 6x = 18

   ⇔ x = 3.

        (x-1)³ – x(x+1)² = 5x(2-x) – 11(x+2)

   ⇔ (x³-3x²+3x-1) – x(x²+2x+1) = 5x(2-x) – 11(x+2)

   ⇔ x³ – 3x² + 3x – 1 – x³ – 2x² – x = 12x – 5x² – 11x – 22

   ⇔ x³ – x³ – 3x² – 2x² + 5x² + 3x – x – 12x + 11x = – 22 + 1

   ⇔ x = -21.

        (x+1)(x²-x+1) – 2x = x(x-1)(x+1)

   ⇔ (x³+1) – 2x = x(x²-1)

   ⇔ x³ + 1 – 2x = x³ – x 

   ⇔ x³ – x³ – 2x + x = -1

   ⇔ -x = -1

   ⇔ x = 1.

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

   ⇔ (x³-6x²+12x-8) + (9x² – 1) = x³ + 3x² + 3x + 1 

   ⇔ x³ – 6x² + 12x – 8 + 9x² – 1 = x³ + 3x² + 3x + 1

   ⇔ x³ – x³ – 6x² + 9x² – 3x² + 12x – 3x = 1 + 8 + 1

   ⇔ 9x = 10

   ⇔ x = 10/9.

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