If CD is an altitude of AABC, which proportion must be true? AB
A)
xo
b
b
B)
AB
b
у
BC
lo
b
у
D)
BC
b
b
х

How do you figure out which order to do two step equations in? like which thing do you subtract/add/multiply/divide first? i understand that you do the opposite of whatever's shown on the opposite side, but when?