<=>(3x-1)(x²+2-7x+10)=0

<=>(3x-1)(x²-7x+12)=0

<=>(3x-1)(x-4)(x-3)=0

<=>3x-1=0 hay x-4=0 hay x-3=0

<=> 3x=1 x=4 x=3

<=> x=1/3

S=(1/3;4;3)

a) 2x³+6x² = x² + 3x

<=> 2x²(x+3) = x(x+3)

<=> 2x²(x+3) - x(x+3)=0

<=>(x+3)(2x²-x)=0

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

<=> x=0 hay x+3=0 hay 2x-1=0

x=-3 x=1/2

x=1/2

S=(-3;1/2)

b)(3x-1)(x2+2) = (3x-1)(7x-10)

<=>(3x-1)(x2+2)-(3x-1)(7x-10)=0

<=> (3x-1)(x2-2-7x+10)=0

<=> (3x-1)(x2-7x+12)=0

<=> (3x-1)(x-3)(x-4)=0

<=> 3x-1= 0 hay x-3=0 hay x-4=0

<=> 3x=1 x=3 x=4

<=> x=1/3

S=(1/3;3;4)