Which shows a perfect square trinomial?

50 y squared minus 4 x squared
100 minus 36 x squared y squared
16 x squared + 24 x y + 9 y squared
49 x squared minus 70 x y + 10 y squared

Average salary for a medical assistant is $31,220 which is a 20% income tax bracket how much money would they pay in income tax?

Serena is making an experiment. for that, she needs 20 grams of a 52% solution of salt. she has two large bottles of salt water: one with 40% and the other with 70% of salt in them. how much of each must she use to make the solution she needs? i am in need of

The data set represents the ages of players in a chess club. 27, 34, 38, 16, 22, 45, 54, 60. what is the mean absolute deviation of the data set?