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