How to write exponential expressions in expanded form

Out of $20$ creepy-crawly creatures in a room, $80\%$ are flies and $20\%$ are spiders. if $s\%$ of the total legs belong to spiders, what is $s$?

Find each value of the five-number summary for this set of data. [note: type your answers as numbers. do not round.] 150, 120, 136, 180, 158, 175, 124, 162 minimum maximum median upper quartile lower quartile

Solve for the equation. 4x - 13 = 2x + 9