1. 7/sqrt 7 - sqrt 3 Rationalize the denominator
2. x-3/x-4 divded by x^2-1/x. state the restrictions on the variable and classify the restrictions as removeable or non removeable
7/sqrt 7 - sqrt 3 , I assume that is
7/(√7 - √3) , that brackets are essential
= 7/(√7 - √3) * (√7 + √3)/(√7 + √3)
= (7√7 + 7√3)/4
(x-3)/(x-4) ÷ ( (x^2-1)/x ) , again, notice the importance of the brackets
= (x-3)/(x-4)*(x/((x+1)(x-1)) )
= x(x-3) / ( (x-1)(x+1)(x-4) ) , x ≠ ±1, 4
Nothing happened here, was expecting some canceling ,
are you sure you don't have some kind of typo ?