Can any kind soul help me please​

What is the missing constant term in the perfect square that starts with x^2 -20x

Darian wants to build a regulation size pool table that is 9 feet in length. he plans he ordered are 18 by 36 inches. what is the scale factor of the dilation he must use to build a regulation pool table

Plz. yesterday, the snow was 2 feet deep in front of archie’s house. today, the snow depth dropped to 1.6 feet because the day is so warm. what is the percent change in the depth of the snow?