a,5(x^2 – 3x+1) + x ( 1-5x) = x-2 b, 3x( 4/3x+1) – 4x ( x-2 ) =10 c, 5x(1/5x -2)+3(6-1/3x^2)=12 06/09/2021 Bởi Kennedy a,5(x^2 – 3x+1) + x ( 1-5x) = x-2 b, 3x( 4/3x+1) – 4x ( x-2 ) =10 c, 5x(1/5x -2)+3(6-1/3x^2)=12
a,5(x^2 – 3x+1) + x ( 1-5x) = x-2 ⇔ 5x² – 15x + 5 + x – 5x² = x -2 ⇔ -15x + x – x = -2 – 5 ⇔ -15x = -7 ⇔ x = 7/15 b, 3x( 4/3x+1) – 4x ( x-2 ) =10 ⇔ 4x² +3x – 4x² + 8x = 10 ⇔ 11x = 10 ⇔ x = 10/11 c, 5x(1/5x -2)+3(6-1/3x^2)=12 ⇔ x² – 10x + 18 – x² = 12 ⇔-10x = 12-18 ⇔ -10x = -6 ⇔ x = 3/5 Bình luận
a,5(x^2 – 3x+1) + x ( 1-5x) = x-2
⇔ 5x² – 15x + 5 + x – 5x² = x -2
⇔ -15x + x – x = -2 – 5
⇔ -15x = -7
⇔ x = 7/15
b, 3x( 4/3x+1) – 4x ( x-2 ) =10
⇔ 4x² +3x – 4x² + 8x = 10
⇔ 11x = 10
⇔ x = 10/11
c, 5x(1/5x -2)+3(6-1/3x^2)=12
⇔ x² – 10x + 18 – x² = 12
⇔-10x = 12-18
⇔ -10x = -6
⇔ x = 3/5
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