Which phase describes the variable expression k-7

Shania's test scores in 8 subjects were 88, 91, 85, 74, 69, 72, 80, and 87. shania found the middle number of her scores. which type of measure did she find?

Find the domain and range of the following function f(x) = 51x - 21+ 4

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?