Marcy played the piano for 45 minutes. she stopped playing at 4: 15 p. m. at what time did she start playing the piano ?

Well, first off 1 hr =60 minutes. 60 min - 45 min = 15 minutes extra. what is one hour before 4:15? 3:15! Add the subtracted 15 minutes to get 3:30... Hope this helps

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

Bis your answer rot d