Please help me with 19 and 20. The first best answer gets brainlist.

In which source of water would a wave travel the fastest? o ice o cold o room temperature o hot mark this and return save and exit next

What values of c and d make the equation true?

Omar is going on a road trip! the car rental company offers him two types of cars. each car has a fixed price, but he also needs to consider the cost of fuel. the first car costs $90 to rent, and because of its fuel consumption rate, there's an additional cost of s0.50 per kilometer driven.