A radio station requires DJs to play 3 commercials for every 21 songs they play. What is the unit rate of songs to commercials?

You give a $4 tip for a meal that cost $22. approximately what percent of the bill was your tip?

An airplane travels at an unknown elevation before it descends 3 miles to an elevation of 15 miles. find the elevation of the plane before its descen.

Can someone plz me understand how to do these. plz, show work.in exercises 1-4, rewrite the expression in rational exponent form.[tex]\sqrt[4]{625} \sqrt[3]{512} (\sqrt[5]{4} )³ (\sqrt[4]{15} )^{7}\\ (\sqrt[3]{27} )^{2}[/tex]