You are on a roller coaster that begins ⅕ km above ground. The roller coaster descends ½ km. What is the roller coaster’s new location after descending? PLEASE ANSWER PLEASE

What is the simplified expression for 6(2(y+x))

Cassie is traveling 675 miles today to visit her brother and his family. so far, she has stopped for gas three times. at the first stop, she put in 7.1 gallons of gas and paid $23.79. at her second stop, she put in 5.8 gallons of gas and paid $19.08. and, at the third stop, 6.6 gallons and paid $20.39. at which stop did casey pay the most for gas?

Elizabeth claims that the fourth root of 2 can be expressed as 2^m since (2^m)^n = 2. find the values of m and n for the case where elizabeth's claim is true.