50g

Im starting a long journey into the world of math, which is not my
best subject. I bought a 50g to try an ease the route a little its
alot more than I need currently but in the future it will be needed.
Anyhows I was playing around with it trying to learn the functions and
cant seem to figure a few simple things out. 

for example if i go into the eqaution writer and type 9-x=3
then select eval it gives me -(x-9)=3 So how would i get it to solve
for x?