Question 191291


sq(3)-sq(4)/ sq(3)+sq(4)
 to solve this, you need to multiply top and bottom by sq(3)-sq(4), in order to eliminate squares from denominator
 so,
 [sq(3)-sq(4)]*[sq(3)-sq(4)]/ [sq(3)+sq(4)]*[sq(3)-sq(4)]
in the denominator you will get -1, which is you got right, because 3-4=-1
 in  the numerator you will get 3-2sq(12)+4= 7-2sq(4*3)= 7-4sq(3). 
 your final answer if you divide by(-1), is : 4 sq(3)-7