What is this pls help me pls

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

Me what is the value of x? showing work would be appreciated - ! : )

Marco has $38.43 dollars in his checking account. his checking account is linked to his amazon music account so he can buy music. the songs he purchases cost $1.29. part 1: write an expression to describe the amount of money in his checking account in relationship to the number of songs he purchases. part 2: describe what the variable represents in this situation.