What value does 4 represent in the number 487.009

Koji is installing a rectangular window in an office building. the window is 823 feet wide and 534 feet high. the formula for the area of a rectangle is a=bh. what is the area of the window? enter your answer as a mixed number in simplest form in the box. $$ ft2

Which number can each term of the equation be multiplied by to eliminate the decimals before solving? 5.6j- 0.12=4+1.1j

Can anyone explain to me how to do this? anything will .