1 (3-x)$^{2}$ + (2x + 1)$^{2}$ – (2 – x)$^2$ – (2x + 1)$^2$ = 0
2 (1 – 2x)$^2$ – 3(x – 1)$^2$ + (x + 1)$^2$ – (1 – x)$^2$ – (x – 1)^2 = 0
Tìm x
Giúp mik với ạ
1 (3-x)$^{2}$ + (2x + 1)$^{2}$ – (2 – x)$^2$ – (2x + 1)$^2$ = 0
2 (1 – 2x)$^2$ – 3(x – 1)$^2$ + (x + 1)$^2$ – (1 – x)$^2$ – (x – 1)^2 = 0
Tìm x
Giúp mik với ạ
Giải thích các bước giải:
`1) ( 3 – x )² + (2x + 1 )² – (2 – x )² – (2x + 1 )² = 0`
`↔ 9 – 6x + x² – (4 – 4x + x² ) = 0`
`↔ 9 – 6x + x² – 4 + 4x – x² = 0`
`↔ 5 – 2x = 0`
`↔ 2x = 5`
`↔ x= 5/2`
`2) (1 – 2x)² – 3( x – 1 )² + ( x + 1 )² – ( 1 – x )² – ( x – 1 )² = 0`
`↔ ( 1 – 2x)² – 3( x – 1)² + ( x + 1 )² – ( x – 1 )² – ( x – 1 )² = 0`
`↔ ( 1 – 2x)² – 5 ( x – 1 )² + ( x + 1 )² = 0`
`↔ 1 – 4x + 4x² – 5 ( x² – 2x + 1 ) + x² + 2x + 1 = 0`
`↔ (4x² – 5x² + x²) + ( -4x + 10x + 2x) – 3 = 0`
`↔ 8x = 3`
`↔ x = 3/8`
1.
( 3 – x )² + (2x + 1 )² – (2 – x )² – (2x + 1 )² = 0
⇔ 9 – 6x + x² – (4 – 4x + x² ) = 0
⇔ 9 – 6x + x² – 4 + 4x – x² = 0
⇔ 5 – 2x = 0
⇔ 2x = 5
⇔ x= 5/2
2.
(1 – 2x)² – 3( x – 1 )² + ( x + 1 )² – ( 1 – x )² – ( x – 1 )² = 0
⇔ ( 1 – 2x)² – 3( x – 1)² + ( x + 1 )² – ( x – 1 )² – ( x – 1 )² = 0
⇔ ( 1 – 2x)² – 5 ( x – 1 )² + ( x + 1 )² = 0
⇔ 1 – 4x + 4x² – 5 ( x² – 2x + 1 ) + x² + 2x + 1 = 0
⇔ 1 – 4x + 4x² – 5x² + 10x – 5 + x² + 2x+ 1 = 0
⇔ (4x² – 5x² + x²) + ( -4x + 10x + 2x) – 3 = 0
⇔ 8x = 3
⇔ x = 3/8