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 – x +1 ) – 2x = x( x – 1 ) ( x + 1 )
( x – 2 )^3 + ( 3x – 1 ).( 3x + 1 ) = ( x + 1 )^3
Ai giải giúp em 5 bài này với, em cảm ơn T^T
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 –
By Remi
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!!!
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.