In order to solve the following system of equations by subtraction, which of the following could you do before subtracting the equations so that one variable will be eliminated when you subtract them? 4x - 2y=7
3x - 3y=15

A. Multiply the top equation by 3 and the bottom equation by 4.
B. Multiply the top equation by 15 and the bottom equation by 7.
C. Multiply the top equation by 1/3.
D. Multiply the top equation by-3 and the bottom equation by 2​

Astandard deck of cards contains 52 cards. one card is selected from the deck. (a) compute the probability of randomly selecting a diamond or heart. (type an integer or a decimal rounded to three decimal places as needed.) (b) compute the probability of randomly selecting a diamond or heart or club. (type an integer or a decimal rounded to three decimal places as needed.) (c) compute the probability of randomly selecting queen or club. (type an integer or a decimal rounded to three decimal places as needed.)