*polynomial in standard form

Question

1)5/12+7/18=5/6
2) 3x/(x+1)-1/(x)=______/x^2-1x

Answer 1

3x/(x+1) - 1/x = (3x*x - (x+1))/(x(x+1))
= (3x^2-x-1)/(x(x+1))
= (3x^2-x-1)(x-1) / (x(x+1)(x-1))
= (3x^3 - 4x^2 - 1) / ((x^2-1)x)