Question and answer updated for 2018 : Former dividend lines 9a and 9b are now lines 3a and 3b.
No, they are not added together. Your qualified dividends are subset of your total ordinary dividends. Line 3b is your taxable amount. Line 3a is merely reporting the qualified dividends portion of line 3b.
Line 3a is broken out because qualified dividends receive favorable tax treatment equivalent to that on long term capital gains. See your "Qualified Dividends and Capital Gain Worksheet" for how they affect your tax obligation.
