What is the sum of the geometric series in which a1 = −5, r = 3, and an = −405?
a: -1220
b: 605
c: -15
d: -605

Most of the people don’t make the sense of taking it

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.

Aye i really don’t know this but i need more point so i am guessing it’s c. 2.0or you can use other apps to you get the answer