Data Sufficiency (DS) | Re: If x = 300 y z, what is the value of x ? (1) y = (x + z)/2

If x = 300 − y − z, what is the value of x ?


(1) y = (x + z)/2

(2) x = (y + z)/2

why is statement 1 not sufficient??

for given statement, x=300-y-z , we can get x+z =300-y and then substitute it in statement 1 right?