What is the y-intercept of the function f(x) = -4.2^x​

10 ! a train starts from grand city and travels toward belleville 388 miles away. at the same time, a train starts from belleville and runs at the rate of 47 miles per hour toward grand city. they pass each other 4 hours later. find the rate of the train from grand city.

Ineed to know the ordered pairs for this equation i need the answer quick because it’s a timed test

Adele is five years older than timothy. in three years, timothy will be 2/3 of adele’s age. what is adele‘s current age?