What is an exponential decay function

Rick is driving to his uncles house in greenville, which is 120 miles from ricks town .after covering x miles rick she's a sign stating that greensville is 20 miles away. which equation when solved will give the value of x. a: x+120 = 20 b: x x120 =20 c: x +20 equals 120 d: x x20= 120

Paul can type 60 words per minute and jennifer can type 80 words per minutes. how does paul's typing speed compare to jennifer's

Tatiana reads 40 pages of her book every night for x number of nights. write an expression that shows the number of pages she has read