Hello,

When solving this type of equation, you mustn't divide. You must factorise, because you miss information this way.

If you divide both sides by 1, you "miss" the solution x=0.

3x(x+4)=x(x+1)

3x(x+4)-x(x+1)=0

x(3x+12-x-1)=0

x(2x+11)=0

the two solutions are :

- x such that x=0

- x such that 2x+11=0