Help me asap now pls

Alocal concert promoter purchases 2 3/4 pages of ads. when one of the concerts is cancelled, the promoter cancels 1 5/8 pages of ads. how much advertising space is the concert promoter actually using?

Write 17/20 as a decimal and as a percent.

If 2(a^2+b^2)=(a+b)^2 then, > a+b=0, > ab=0, > a=b, > 2a=b