Question 42698
a)sq rt x^2 = x .. True. you have another answer also in -x.
b)sq rt x^2 + 9 = x+3.. False ..when RHs is squared we get x^2+9+2x ..OK
c)2x+y/4=x+y/2 True ..both sides are didvided by 2 
d)sq rt 1-x= -sq rt x-1 False 
since
sqrt(1-x)=sqrt(-1)*(x-1)=-i*sqrt(x-1)an imaginary number